Maniac
Apolyton Sage
The Human Hive
for a second I considered suggesting Sprawling trait from FfH, but then I realised I really hate that trait![]()
I was planning to give that trait to the Caretakers.

* No Tech Brokering is turned on for all factions, but Zak and/or Roze is exempt from it.
That sounds cool if you're playing Zak or Roze. However a problem I see: if I was playing against them, I think I'd never want to trade with those guys then.
* Morgan is exempt from the new rule regarding access paths for trade - he can enter trade agreements with anyone he has Open Borders with.
But that would just turn their trade route advantage into an automatic bonus, and as a consequence not affect their playstyle at all. Needing open borders with everyone to put their trade advantage to maximal use, that actually affects how the Morganites approach the game.
What if the Morganites spread a number of different corporations, whereas the Believers would only want to spread their one "true" religion?
That doesn't change the similarity that with both factins you'd be spending a lot of your playtime moving units to other civs's bases. IMO Boooriiiiiiiiing.
To counter this, the Morgans should only get these bonuses for corporate offices in Factions they have open borders with. This would drastically change the game mechanics for the Morganite faction making playing them all about trying to keep things friendly and spreading corporations as much as possible.
How is the result different from just giving the Morganites a bonus to all their trade routes? That results in the same drive to seek open borders with as many people as possible.
I will try to think of more suggestion but since I have no idea what is feasible to mod I'm not sure how much of it will be useful...
I know I just said you don't need to let your imagination be restricted by what's possible in the XML, but I have no ideas how to translate any of your ideas so far to game code. :-s