For the reproduction characteristic, its cost to increase seems to be 50 points in the PvK balance mod, that is cheaper than in AIC. Granted, I will keep such criticisms from when you have done adapting PvK Balance Mod for AIC 4.0
(A very... erh... balanced mod incidentally) And yes, to have low reproduction on not very populated worlds is intentional for Proportions and AIC.
As for the events, well, chances settings have been reported to alter the results, but is that pure randomness (not likely) or is there something hidden there? At least, I believe we can all agree Homeworlds *can* be targeted by events under certain circumstances at least?
But how unfrequent would it be with Heroes and the new events file for AIC 4.0, with numerous Empires? I fear there will be a lot of testing and tweaking with regards to these events, except if someone manages to find out the way they are working.
(Of course, if you need me for testing something, I would gladly do so. As long as you don't ask me to do actual modding.
)