Nobody is really modding the AI except for myself and another player making AI for their BSG mod. Perhaps when I release v1.20 of the Balance Mod, I'll hold a tournament of the AIs in the mod.
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For question #3, it's relatively easy to add a condition where if the AI has X resources in storage and a surplus production, then build a storage facility on planet Y. It's only going to help a bit with the AI and finite resources since they're construction routines are not designed with conservation in mind.
For question #4, you could run a one-time event via the Events script after the first turn to adjust all the values of planets in the game.
Both are not difficult to do, but does require understanding of SE5's AI scripting.
Wiki link on the basics:
http://wiki.spaceempires.net/index.p...t_Editing_(SEV)
The Balance Mod AI scripts are setup a bit differently then the stock scripts, but their general handling is the same.