OK-
1st- I only play on tough, so this is the AI at its best game
2nd- these are some tactical issues the AI needs help with IMO
A- The AI needs to value speed more, I've yet to see an attack ship with engines. Half of what makes the dread lords so challenging is that they can move about so darn fast, and with only 2-3 moves a turn the AI is basically cripled IMO.
B- The AI needs to change its threat analysis. It has to go for soft targets like military stations. I planted one military base with quite a few bonuses in a system and got attacked by the drengin, korx and yor, all with supperior fleets. But becasue they only went for my ships and not my military stations, they got wiped out. Of course I attacked there fleets when they got into range, so again having faster ships would help immensely. Also the AI needs to start attacking AWACS ships (cargo hulls packed with sensors) They're critical to any decent tactical analysis and make a huge difference.
C- Unescorted transports. This has been reported multiple times, so I wont elaborate. Its ok to have unescorted transports, but the AI needs a safe distance algorithm so they dont ram em right next to my fleets
D- AI fleets should spread out more often. In the above mentioned siege of my system with a military base, the AI used these mega stacks with 3-6 fleets in them, which means I could attack them repeatedly. If they spread out I wouldnt have been able to attack them so often in one turn (thus negating the all-important fist attack bonus) and would have been able to take out my crucial military station.
E- This isnt really a tactical issue but it applies: The AI needs to specialiaze its weaponry. Its ok to switch weapons if I have strong defenses (which I never do: my strategy is based on attacking first with big guns, fast ships and recon from AWACS) but the AI values weapons tech in much the same way as other tech, which is to say that it'll trade for it even if it doesnt need it, this not only means the AI ends up having lots of different mediocre weapons, it also means it rarely gets high level weapons like the nano ripper (which I worship, is unbalanced and needs to be nerfed).
Just some thoughts, I have a lot of other things but I cant think of them right now. Post anyideas you have