Thanks for this reply. I am not sure that we can create unlimited customized event with Google Analytics. We search for a solution that can store every single event composed of many information (userId, time, event, sessionId, IP by exemple) and another solution to manage all the recorded data to analyze them.
There is a limit to the amount of events a session can generate in Google Analytics (500 events/pageviews), therefore you'd have to figure out what information is relevant to track and what's just noise.
From the sound of it you will need to go down the self hosted solutions path if you are wanting to have that level of tracking (assuming you do not want to cough up the 80k+/year on Omniture or the like). Perhaps someone else here can recommend something more suitable.