Age Transition Carry Over Mechanics.

While recently transitioning from the Exploration to the Modern age, I decided to do some testing and I discovered that on standard speed, diety, your Gold will carry-over, but caps out at 3k.

I also noticed if you have yet to unlock a Civ unique Civic that increases your settlement limit, IT DOES NOT auto-unlock that limit increase when you transition. So unlocking all Civ Unique settlement limit increases is a HUGE priority in every age. (Thanks for SeriousTrivia for clarifying this).

Same thing for all traditions, they do not auto unlock so if you do not research them, you never will get it. (EDIT this was wrong).

I am wondering if anyone knows any other mechanics of transitions?

Are all age transitions capping carry-over gold at 3k? Does game speed affect this? Difficulty?

Is influence capped? I know I carried over 600+ surplus influence in this saved test.

What decides if a commander has units placed in their stack? I sometimes have 0 units, sometimes I have 6. Is it based on their logistics comendations? Is it based on their level? Their type? I have noticed that navel commanders often have units in their stack but army is much more rare.