Alneyan,
From my not-so-large experience and readings, that's what I suppose about AI behavior :
Low Indy strength results eventually in AI demise, because the AI expands too quickly and send small armies all over the map, that pose no threat to player. OTOH a very high Indy strength makes it difficult for the AI to expand initially, so indy 5-7 is the best AI ally !
AI sucks with magic overall, so I feel that hard research makes things harder for player and not that much for an AI that will never properly use Rituals, Communions or gem-consuming "heavy" battlefield spells. The same goes for site freq - human players can properly manage their income more than an AI.
Another obvious AI helper is the difficult settings that give them more design points and income - unfortunately the AI overloads more than not its pretender and never take great scales, nor does it build much castles (surely 'cause it doesnt spare money to do so..).
My 0.02 € cents
