For that last game I tried and failed to run, my main inspiration was the 7th century and the strong decline of both the Persian and Eastern Roman empires. Both empires had badly bled each other's military, orphaning city states in the region between them, city states of whom none had their own army (since the empires had military monopoly until then). Travel became dangerous, trade collapsed and suddenly, for a lot of people, the world became a more dangerous and much smaller place.
(Eventually, Arab tribes, many of whom had worked as mercenaries for empires in the period before, managed to leverage the military weakness to seize the whole region and even the remnants of one of the empires.)
Yay! Now, I'm hesitating between a cat or a spider...Yes, you can certainly start with your familiar.
Yeah, well, otherwise it might be too strong for a cantrip. The use of True strike that I see is mostly before combat, when waiting in ambush or going for an assassination. The fact that it only has a somatic component helps a lot with that kind of situation.This lets it counteract particularly adverse circumstances. The default True Strike's action economy just isn't worth it most of the time, and it overlaps with Find Familiar somewhat by having your familiar use the Help Action in combat. Those are my thoughts on it anyway.
Theurge's flavor is not what I'm aiming for with this character. Moreover, my character is slot-starved, so I'd prefer to go with a tradition that gives me some kind of extra power, not extra spells to cast.If you haven't looked at it yet, consider the Theurge Arcane Tradition to pick some cleric spells, or the Divination one to pick up portents.