i agree that total posessions are a fundamentel piece to produce realistic stats. i pointed it out earlier and i could repeat in the suggestion forum, if it's requested.
one major problem are lines like this:
3:46 Player A takes a three point shot
3:46 Player B pulls down the rebound
so you are taking no time of the clock, and this is huge i think. just take of 2 seconds for a 3point shot, 1 second for every inside shot and a MISSED 2nd (3rd) freethrow (i know, dunkings won't take 1 second, but an average value will do fine) and take 0 seconds of the clock, when a shooting foul was comitted, the new 24 seconds start with the rebound.
As a simple example take a "normal" BB-Game with 90 shots per team. this will make 180 shots and maybe 10 missed freethrows leading to a rebound. so we are talking easily about 3 minutes of playing time if you take at least 1 second away, every time a rebound takes place! i guess, this would be a great first step and this shouldn't be too hard to implement.