study the players.. emulate their behavior in the ai.. for example, allow the ai to buy metals or crystals when it needs them, or right off the bat.. make an ai option for zerg rush option, where it builds a couple of scouts to find you, then a cap and a bunch of lrms to rush with..
Make a non rush ai that develops many/all of the caps, then sends them out in teams, or all in one armada.. have the ai use the train crews option after all the neutral stars are taken and it is apparent that xp is gonna be harder to get..
Instead of all platform defense, make it sometimes use hangar defense, phase space inhibitors, and overlapping repair stations
Have the ai evaluate the map to find chokepoints and then fortify the heck out of them.
Put a bravery variable into the ai so that it'll range from fight to the death, all the way down to flee at 20% damaged

stop the ai from cheating..

when I set a structure to scuttle, it is amazing that the ai stops attacking it and then goes on to it's next target, so I cheat back, and then cancel the scuttle

have the ai evaluate positional data on the defense platforms, not just the number of them, or greatly increase defense platform range so they can almost hit anywhere in the gravity well (reduce effectiveness for range perhaps?)
Figure out which structures currently don't get targeted for whatever reasons and give them some weight.. like frigate factories, pirate/neutral gun platforms, etc.
ok, there's my constructive criticism for what it is worth