R6-9.5 stats would be fun
I like the idea of allowing small bps (definitely no more than 4) mixed with a decent number of randoms and small private gals.
Only allowing self exile would be fine if the scraping of truly inactive junk planets to c200 is more aggressive (e.g. after 24 ticks).
Cluster def eta advantage and several small clusters could certainly be fun.
I don't think anything trying to enforce specific behavior in the meta-game is ever going to work right. (e.g. trying to force no cooperation/avoidance between gals, it's just as dumb as trying to enforce "good" behavior in havoc)