Facebook Graph API or FQL to track fan page user activity

Facebook Graph API or FQL to track fan page user activity

I need to track the activity of a user in a fan page, that is to measure
how much active he is in that page. A possible way to measure this would
be counting the number of posts the user has liked and shared. Here is
what I tried to do without success:
Fetch data using FQL's stream table: according to some stack overflow
posts, the stream table returns only 50 tuples or posts no older than 30
days. As I need to analyze a bigger data set this alternative seems a dead
end
Fetch data using graph API: There's no way to get all the posts the user
likes, only is possible to get which fan pages he likes. We could process
each post on each fan page, but the problem is that this would require
tons of request to Facebook to navigate across posts and likes cause we
need to determine if the logged or a specific user likes each post.
Thanks! Martín