Thanks, Aaron.
Followup on the Matrix stuff:
When taking a hostile action against a device that is not his (i.e. brute forcing an opponents commlink, or spoofing a drone), in which device does his persona reside?
The one providing the persona. In SR4, you could enter other people's devices. In SR5, the only thing your persona can enter is a host.
And by the way, I presume that you meant to say "Nope, only when making defense and resistance tests" 
You're welcome to presume that, but you'd be wrong. Defense tests are the ones you use against actions (the bit after the "v." in the test description). Resistance tests are for things like resisting damage. Slaving helps with the former, but not the latter.
Also, given the apparent ruling on AoE tests; what's with the -2 defense penalty when "defending against an AOE attack", then? When would that ever apply if you don't get a defense test?
It would never apply because it's an error that I believe will be removed in the errata when it is released.
Lots of rigger-related questions.
1. Page 264 mentions "other devices" as things that can be rigged and the security spider is reminiscent of the old CCSS rigger. Is there a way for a rigger to get marks on a device so s/he can use the Control Device matrix action?
2. What does a rigger roll to drive a vehicle while using cold- and/or hot-sim? Presumably not Reaction since the rigger is a rag doll.
3. Similarly, what does a rigger use for initiative while using cold/hot sim? I'm assuming it's also Data Processing + Intuition (+dice as appropriate).
4. Can you give an example of a Matrix action that would share a bonus with a Vehicle action (p. 266, under "VR and Rigging")? For example, does the +1 die to Vehicle and Matrix tests while using hot sim (p. 266) stack with the +2 dice to Matrix tests (p. 231) since "any bonus you get to Matrix actions also applies to Vehicle actions."
5. A rigger is running hot sim on his Optix-X2 scouting an area for potential threats. Does he get to pick between Perception + Intuition [Sensor] (p. 270) and Electronic Warfare + Intuition [Sensor] (p. 445) for the roll assuming he's using his sensor array. Is there any reason not to use his sensor array?
6. How are sensor arrays priced? Are any eight functions from the table on p. 446 essentially free, but after-market modifications (a thermographic modification for your free camera (3), for example) out of pocket? If the functions aren't free, where are the prices?
7. Going back to the interchangeability of Perception and Electronic Warfare in question 5, can a rigger use Electronic Warfare for a sensor test (p. 184)?
Non-rigger related question:
8. How does a dart of narcojet interact with armor? Without a power or AP rating for the dart pistol/rifle, it's hard to know how to determine if the dart can deliver its payload. A guy in full armor is going to be tougher to take down than a pedestrian.
1. Yes, the same way that hackers do it. They can't jump into a device that doesn't have a rigger interface, though.
2. Reaction. It's the same medulla oblongata and motor cortex, it's just the signals go to different places than Mother Nature intended.
3. Data Processing + Intuition.
4. Yep, your example is correct. Rigging is awesome (until you get hacked or totaled).
5. Yep. Possibly, depending on the situation.
6. Single sensor functions cost Rating x 100¥, arrays of eight cost Rating x 1,000¥. Since your vehicle is big enough to not have to worry about sensor capacity, I suggest you buy them individually at your vehicle's Sensor rating.
7. I think this was already answered in 5.
8. Injection darts, p. 434, SR5.
Okay, I can see that this thread is not going to stay on just clarifications on rules, but will be questions as well. As such, I'll merge it with the FAQ thread so we have everything in one place.
Thanks, FastJack!
Q: What is allowed to be added to a helmet (i.e. using capacity)?
Trode nets and vision enhancements are listed specifically, and both have known capacity ratings, but what about other equipment like communications gear (jammer/headjammer, white noise generator, etc) audio enhancements, survival gear (respirator/gasmask, flashlight ala Aliens Marines), sensors, etc.
Sounds good to me. Check with your GM to be sure.
Q: What, if any, is the recovery time for installing cyberware that costs capacity instead of Essence, such as a cybergun or a commlink in a cyberlimb, and how does this affect training times?
The recovery is based on Essence cost. Since there's no Essence spent, there's no recovery time, and it doesn't affect training times.
Xenon, so in all of my above examples the decker (B) would be affected by Noise generated by the jammer carried by A? Makes sense; didn't catch the part about hosts.
Another question that's been asked before (page 5) but that I'd really like an answer to:
P. 141/142, "Using Leadership" :
How long does the potential Initiative bonuses from the complex action "Rally" last?
1. Until the next combat turn as per the "Changing Initiative" rules on P160, or
2. Until combat ends as there is no duration stated, or
3. Something else
The answer is 1. The Rally use of Leadership is an instantaneous bonus, added immediately the same way that taking an interrupt action reduces Initiative Score immediately.