I played BBAI for the first time after a while last weekend and here are my observations. Not everything I list is necessarily "questionable" but I had a hard time deciding where to post so forgive me.
This was a Prince game, normal speed, a standard size-pangea-like custom map, standard settings.
1. AI built WAY TOO MANY ships. When Zara declared on me, he had about 3x advantage in the power graph but I quickly found out that about 80% of his power was destroyers. He eventually sent them against me piecemeal to kill fishing boats but didnt matter much in a pangea map. I ended up winning the land war suprisingly easily. This is doubly questionable beacuse he declared on me counting on the power of his destroyers.
2. Caesar desperately needed oil, which lay just on the other side of the border on my side. We were same religion but at "cautious" almost all game and he had many opportunities to backstab but... you guessed it, he sat on his huge army WHOLE GAME.
3. The AI doesn't take advantage of its unique units. Some of the earlier UUs are pretty powerful. It would also add to the roleplay/flavor aspect if AI was more aggressive when its UU is in play.
4. AI still did a poor job going for victory towards the endgame. At least two AIs were in good shape tech-wise but were suprising slow to start constructing the spaceship. They just emphasize units, which is wise if you eventually use them but wasted if you just sit on them.
5. At Prince, AI builds a tad too many cities. At higher difficulties this is probably good for AI with all the bonuses it gets, I dont know for which difficulty better AI is supposed to be optmized for.
Just my two cents....