I don't know if these have been mentioned before, but I have a few suggestions regarding how the AI uses its events:
1. Several times, I've seen the AI play an event that gives a bonus to Combat Doctrines research in August 1914 for two turns. My understanding is that Combat Doctrines can only be researched during Grand Offensives, which begin in 1915. Thus, playing such an event in August 1914 is a waste - the AI should be programmed to not play such an event until 1915.
2. In one game, in addition to playing an event to steal East Front plans, the AI played two events (IIRC Mata Hari & Espionage) & used them both to steal war plans from the Western Front. Obviously this is a waste of one of the events - in such a case, the AI should be programmed to save one of the events for later.