Generalist
I wouldn't break the 5th level cap with Limitless Potential. A few extra slots is fine, though.
Enduring Magic is either really good (if the DM likes tossing counters your way) or basically useless (if not). Not a very good general feature.
Superior Concentration is interesting, but I'd require you to spend an equal slot level, not just total slots.
Spell Potency feels perhaps too good, perhaps not. I'd want it tested.

Void
Why only non-magical sources? I wouldn't grant cold immunity to all cold, but resistance to all is fine.
CD is weak, but cool.
Grasp is cool.
Potent Spellcasting is standard.
Acausality probably shouldn't allow disadvantage on the save. Grasp of the Void is kinda niche, whereas damage is not.
Overall, though, I really like this one! It's cool as heck.

Mega Corp
Personal Investment should allow for any trade good-100 GP is 2 lbs, 100 GP of gems is much lighter. I might slap a "Prof Mod per Rest" clause on it, to avoid abuse, though.
That might be a bit too much Artificer-perhaps slow the rate down.
Tireless Dedication feels a mite too good.
Product Recall should only work on single-target spells, or if ALL creatures pass their saves.
Bankruptcy has the wrong level listed. It's cool, though.