Hi Jalal, I will look into your code soon, thank you very much!
I plan to release a premium version of this plugin at http://www.q2apro.com/
1. needs no cronjob anymore
2. caches all userscore values
3. has all settings in the admin panel (free version has not...) to make the plugin userfriendly (even for non-programmers)
Just need a bit more time, will report back!