Where are you seeing 4 Potency at most? I mean, 6 dice is likely to get 2 hits, but that's fairly likely to get fewer hits. Even with my not so amazing 14 dice, I am fairly likely to get 5+ hits. I can always reroll the super important high force spell with Edge if I need to. The Potency time limits are not that bad, as 8 hours before a run is not terrible. It is a thing to deal with, I grant you that. Drain is also sort of annoying, but 4 drain is not impossible to deal with when I have 11 dice to resist. Also, if it's still stun damage, I might be able to nap it off before a run. It is still a pretty annoying thing to deal with.
Two hits is the average of six dice-- It's "fairly likely" to be higher or lower, but that's the most common outcome. You can use Edge, but then you're using Edge for one mediocre spell... My point is that you'll likely hamper yourself if you try to be a combat alchemist as your focus.
Here's the thing about the potency time limits. The hours before and between you'll need to use for resting. Four Drain from a F6 Command Lightning Bolt isn't bad, but using the Fireball preparation will be tougher. At F6, you'll probably end up with 3-4 Stun from drain (8 DV, 12 dice on Drain Resist would average 4 hits). With 8 dice from BOD+WIL, that'll take one or two hours to rest off. For every 3 drain you actually take, that's an hour of rest needed, and unless you're doing relatively low Force spells, you're likely to take drain. And lower Force spells (4 or below) thus last a shorter period of time and have much smaller dice pools (a F4 Preparation is likely to have a dice pool of 7 to cast with...)
So assuming you're doing things at least at F5 (where you're likely to get at least 9 dice for the prep to cast with, which is still kinda low) and with your list, most things will cause around 6 Drain, of which you can probably expect 4 resisted. The potency will probably be 4, so they'll last 8 hours. Assuming you don't mind taking the wound penalties (and for simplicity, assuming they don't impact your preparations) you could make about... Eight preparations?
8(number of preps) x 2(average drain) = 16 / 3(stun recovered in one hour) = 5.3(hours needed, approximately). This leaves you a bit less than 3 hours for travel time and what have you before you start losing preparations. If say, the job is like 15 minutes away and everybody's already fine to go and you can work up right until the job starts, you could get away with about 11 preparations.
Which is a decent number of spells I suppose, but they'll all be less effective than if a sorcerer used them (with a higher dice pool, and taking 2 less drain per, meaning 0 on average) and completely locked in.
This is what I call "The Alchemy Problem".
The better your preparations are, the less and less of them you can have, and the bar starts much lower than it does for sorcery. Currently, the "benefit" of alchemy has enough built-in drawbacks that the other drawbacks of alchemy just drown it out.
I do have a few ideas of creating an Alchemist with A for magic, so I get a few more spells in there. For now, what do you suggest me dropping for Increase Reflexes? Sound barrier perhaps? I could create a bunch of Improved Invisibility and Increase Reflexes preparations before hand to leave around for people to buff themselves. Like, "If you get in trouble, pick up this credstick and say 'Cloak me from my enemies, shield me from their sight'. You will become Invisible for a time."* More of a utility thing than combat related. Although I could always hand the face a credstick with a Command Trigger Knockout spell for them to activate when they "bribe" the guard.
I'd suggest Sound Barrier dropped for Increase Reflexes, but that's just me.
People can't activate your preparations unless they're Contact, in which case they couldn't carry them around beforehand. If you can't be there to activate them (which requires LOS and a Simple Action, and can't be done from the Astral unless you Manifest) then your best bet would be either hiding contact preparations around the run site, or giving everyone timed preparations to all go off at a certain time (which is always just after an amount of time, but you could say "I am gonna time these all to go off at 5:30").
Alchemy is the Technomancy of magic. A more difficult way to do the same thing (as Sorcery or decking, respectively) but worse, unless you figure out a very niche role for yourself or a specific trick.
