Did I just scare everyone off?

Ummm ... all those last arguments about what was and wasn't correct historically is NOT in a world of magic ...

That and generally in Pathfinder, it is you and your companions versus some baddies ... not an entire army of knights on horseback charging down on you.

To get back on track -- I think the firearm rules are good as they are giving AoO for firing and reloading.

My guys especially like it when they come across baddies with pistols firing at them ... my rogue's Step-up really upsets both casters and firearm users who try to use their 5' step

Well, tbh, it's up to the GM to create any scenario they like and stretch the rules in whatever way they can. At least, that's the virtue of game design or fresh encounter planning.

The act of aiming provokes AoO, but you shouldn't have to aim at an opponent right in front of you. It seems simple enough to rule AoO when you're not attempting to shoot a foe that's flanking you or right in front of you.

And if you accidentally shoot a foe in front of you, it occurs in the event of missing an opponent far away.

What about penetrating cannonballs? Hitting multiple foes in a line? Bouncing cannon balls? It's all about scenarios.

It's whatever is coolest. Which is basically whatever the GM thinks.