So the plan now is what? If tourney performance is a consideration then ...
. place as few expansions as possible and NEVER EVER buy a Premium expansion
. build the minimum number of AWs that actively help with tourney; delete/do not build all others
. do not advance through chapters that will not add reasonable value. or when advancing, consider what other AWs could be deleted to compensate, or other ways to compensate?
. any other hints?
Well if you want to build a tourney town, you are better off placing Premium expansions ONLY, while leaving all the normal ones you get to rot in your inventory. Obviously nobody would want to spend money on such an experiment, because it has nowhere to go after a certian point, but Premium expansions are definitely better than regular ones.
However simply playing smaller cities makes sense now if you combine it with the stopped chapter progress in the end of the game. You can play the game with much less space now since you don´t have to bother with guest races anymore (use PP instead) until you reach chapter 15. Then once you do need a guest race for a while, but just the once, so it is still manageable...
About AWs: yes basically that, however it has always been like that, the difference is now you get punished for building the useless AWs while before it was simply a waste of your resources (which is a milder form of punishment) ...
As to chapter progress, I think there are a few sweet spots that could be used, but none of them include playing chapter 16 (or any future chapters). However if you want to progress I see no reason not to progress until you reach the Frogs tech in chapter 15.