Need advice on cleanning my db
 

now that im running 3.5 there are alot of old files in my db,
can anyone tell me how to find what files are not need any more like ones from old hacks that are no longer used.

depends on what hacks etc arnt being used. If you go into phpmyadmin you should recognise most of the tables you arnt using anymore

Look through install/, there should be a file with all the definitions of tables it needs.

Create a test forum using a fresh install and compare the table list (and fields if you really want to).