You should totally give me some supply tips.

But, seriously, how are you doing with a fleet, and defenses, and research? It's a balancing act. I can do really well on the economic and research, and my fleet hurts as a result.

The AI doesn't seem to fully develop it's worlds or research, so I don't think it's so much that the AI isn't spending it's money, but often doesn't have it to begin with. It also seems to like upgrading it's fleet's capacity very early (no other way for it to produce that number of Siege Frigates as well as it's fleet, since those Siege Frigates eat population cap). So I don't think it ever really gets the cash flow going to begin with (although late in game if Pirates are still around the AI sometimes proves to have a substantial store of credits around).

Hopefully this kind of thing can be worked on in future patches.

Yep, AI planets are usually not well developed.

In addition to that I usually see the AI do nothing but spam MASSES of light frigates. For those they have to upgrade their fleet cap quite early - which means even less money (and no even remotely useful fighting force either since they don't build advanced ships).
Especially in research the AI does basically nothing.