[Stainless Steel Devil Rat]

Agreed, but I like to interpret the rule as also applying to pedsetrians shooting at moving vehicles (and people in/on said vehicles). 

[Odsh]

Drivers should track their own speed.

So you have less chances to ram an immobile vehicle than a fast moving one?

[Odsh]

A drone has a number of slots for autosofts and other Matrix programs equal to half its Pilot rating, rounded up. If a drone is slaved to a rigger command console, it uses the programs running on the RCC. This can exceed its normal limit.

So rigger programs are installed on the RCC and drone autosofts are installed on the drones, but in the end the drones benefit from both.
Is it possible to install an autosoft on the RCC so that all drones in the network benefit from it without the need to install it on each drone?
Is there some kind of copy protection mechanism that forces the rigger to buy a separate instance of an autosoft for each drone?
What is the max rating for drone autosofts? 6 I assume?

[Stainless Steel Devil Rat]

Drivers should track their own speed.

So you have less chances to ram an immobile vehicle than a fast moving one?

You track your own, so it's irrelevant how many speed interval dice your target is suffering.

The potential exception I mentioned in my own post is applying the driver's speed interval penalty to external actors on foot who are targeting that driver/vehicle/passengers but have no speed interval penalties of their own.  As a sort of of penalty for shooting at a fast moving target, since there is none... rather than reserving that consideration to circumstantial edge.  That's not official however.

A drone has a number of slots for autosofts and other Matrix programs equal to half its Pilot rating, rounded up. If a drone is slaved to a rigger command console, it uses the programs running on the RCC. This can exceed its normal limit.

So rigger programs are installed on the RCC and drone autosofts are installed on the drones, but in the end the drones benefit from both.

Somewhat correct.  You can run Autosofts directly on drones.  And technically there's no limit to the number of Autosofts you have loaded on a drone, there's only a limit on the number of Autosofts a drone can benefit from simultaneously.

For example:
If you have a little Pilot 1 spy drone, you can load Clearsight, Maneuvering, Stealth, and Evasion all onto it.  But it can only use 1 at a time.  (not including what may be shared from a RCC)

Is it possible to install an autosoft on the RCC so that all drones in the network benefit from it without the need to install it on each drone?

Yes.  that's what the Sharing mechanic is for. See pg. 197

Is there some kind of copy protection mechanism that forces the rigger to buy a separate instance of an autosoft for each drone?

By RAW unclear, but the intent is that if you want X copies of a program you have to buy X copies of a program.

What is the max rating for drone autosofts? 6 I assume?

Per Jan 2020 errata, max rating on Autosofts is 9.

Edit: also note that autosofts can be run on and shared to passenger vehicles!

[Xenon]

Drivers should track their own speed.

So you have less chances to ram an immobile vehicle than a fast moving one?

Not sure I fully understand your line of reasoning there....?

Your negative modifier seem to depend on both how fast you are actually driving but also how well your vehicle handle speed.

You typically have less chance to hit if are in a crappy vehicle that can't handle speed than if you are in a sporty vehicle made for high speed. You typically have less chance to hit if you are in a vehicle that is speeding than if you are in a vehicle that is not moving at reckless speeds.

To ram an immobile object you typically don't have to drive very fast at all (= easy to control)
To catch up to, and ram, a fast moving vehicle you typically need to drive a lot faster (= difficult to control).

So, to figure out your negative modifier it seem as if you need to track your speed.

SR6 p. 199 Vehicle Rigging
Speed Interval is a measure of difficulty in driving the car—the faster the car, the trickier it is to keep under control, though some cars handle speed better than others. Drivers should track their current speed; each time they pass another Speed Interval, they incur a cumulative –1 dice pool penalty to any tests involving Handling for the vehicle, as well as attacks from the vehicle.

So rigger programs are installed on the RCC and drone autosofts are installed on the drones, but in the end the drones benefit from both.
Is it possible to install an autosoft on the RCC so that all drones in the network benefit from it without the need to install it on each drone?
Is there some kind of copy protection mechanism that forces the rigger to buy a separate instance of an autosoft for each drone?

Yes, drones can benefit from an autosoft running on the RCC it is slaved to or an autosoft that is running on the drone itself, but it seem as if each drone type and model have a different version of the same autosoft. They don't seem to be compatible between different drones.

What is the max rating for drone autosofts?

9

SR6 Errata Feb 2020 p. 6
p. 272, Software table
After the word Autosoft, add “(Rating 1–9”) to provide a range for Autosoft ratings.

Somewhat correct.  You can run Autosofts directly on drones.  And technically there's no limit to the number of Autosofts you have loaded on a drone...

At least in previous edition 'Load' a program was the same thing as to 'Run' a program.

So what I think you meant to say was;

No limit of Autosofts you may have 'stored' on a drone.
Limit is on the number of Autosofts a drone can 'run'.

SR6 p. 184 Programs
The Data Processing rating of your device limits how many programs you can have running, though more may be stored.

...there's only a limit on the number of Autosofts a drone can benefit from simultaneously.

There is only a limit on the number of slots a drone have to run programs directly on the Drone itself.
If slaved to a RCC it can instead benefit from Autosofts that are currently running on the RCC.

SR6 p. 201 Autosofts
A drone has a number of slots for autosofts and other Matrix programs equal to half its Pilot rating, rounded up. If a drone is slaved to a rigger command console, it uses the programs running on the RCC. This can exceed its normal limit.

[Odsh]

So you have less chances to ram an immobile vehicle than a fast moving one?

You track your own, so it's irrelevant how many speed interval dice your target is suffering.

Not sure I fully understand your line of reasoning there....?

I'm not referring to the attacker, but the defender.

Determining if you hit something with a ramming attack, like any attack, is an opposed test. My point is that the defender is less likely to score hits when he's faster. Ergo, you're more likely to ram a fast moving target than a slow or stationary one.

The only thing that matters in the end are the net hits. In that regard, adding or removing dice to the attacker has exactly the same effect as doing the inverse for the defender (barring Edge shenanigans).

It's the same kind of weirdness as your example of someone shooting at a fast moving vehicle.

[Stainless Steel Devil Rat]

Ah I see what you're getting at.  Speed interval is not a universal penalty.  I believe the intent is that it does not apply to dodge/defense tests, although I can see how it's confusing since it says it has to do with "handling tests".

[Odsh]

I think you're right, I misinterpreted the "in either case" below:

The attempt to hit another being or vehicle is an Opposed test—Piloting + Reaction vs. Piloting + Reaction if you’re trying to hit another vehicle, or Piloting + Reaction vs. Intuition + Reaction if you’re trying to hit someone outside a vehicle. Speed Interval penalties (p. 199) apply in either case.

Speaking of dice pools for defense, is it also Piloting + Reaction for attacks other than ramming?

[Stainless Steel Devil Rat]

If someone is attacking your vehicle or drone it's still Reaction + Intuition while you're in control of it.   Pilot + Evasion autosoft is only for autopilot.

[Odsh]

*yes this is a point of dispute with some, as the text is admittedly ambiguous as to whether the intent was a limit of +4 skill ranks or +4 bonus dice to a skill test.  To the best of my knowledge the intent is the latter, but adding this caveat to acknowledge that the only clarification on the subject was not formal errata.

On an interesting sidenote, the rules for creating custom spells in Street Wyrd make a clear distinction between the two following ingredients:

Affect specific type of test
When this ingredient is selected, choose a type of test. This has to be narrower than a single skill—for example, Blade attack would be appropriate, but Close Combat attack would not be. Similarly, a Lockpicking test could be selected, but not any Engineering test. All tests of the selected type get +2 or –2 dice per 1 point of Drain the caster adds.

Skill boost
A specific skill must be selected for this spell. The maximum skill bonus is +4. Drain: Caster rolls a Sorcery + Magic (5 – Essence) test; each net hit increases the skill and the Drain Value of the spell by 1.

[Odsh]

If someone is attacking your vehicle or drone it's still Reaction + Intuition while you're in control of it.   Pilot + Evasion autosoft is only for autopilot.

Well it's Piloting + Reaction when defending against a ramming attack at the very least.

Would the Reaction + Intuition then become 2 x Intuition in VR and when "jumped in"?

[Xenon]

On an interesting sidenote, the rules for creating custom spells in Street Wyrd make a clear distinction between the two following ingredients

...but both of them still use the same up to a total maximum of +4
Just that in the first case you only get a positive dice pool bonus to your close combat skill if you are specifically using blades or your engineering skill if you are specifically using lockpicking.

[Stainless Steel Devil Rat]

Would the Reaction + Intuition then become 2 x Intuition in VR and when "jumped in"?

When you're rolling something else in place of Reaction, then of course it's (Substituted Stat) + Intuition

[Odsh]

All right, I updated the table with everything that was said so far: link.
Am I missing anything?

[Stainless Steel Devil Rat]

Well it's clear there's no special rule for stealth while driving/commanding a drone, so technically it's still Stealth, with a presumably reasonable switch of attribute from Agility to Reaction.  But Xenon's suggestion of "lower of stealth or piloting" is quite a fine house rule. (Which may not be a meaningful distinction if your doc is for your home game)