1) is possible to read the files from WF3.0 to Wf2.0?

Backward compatibility is not possible in Pro/E. If you want it desperately then you can buy one of the extensions just for conversion. Even after that many options will be disabled when you open it in ithe lower version.

2) Are there differences between wf3.0m10 and wf3.0m30 ?
Tanks!!!

When a datecode is released certainly many bugs are fixed and few options improved. Look for PTC's technical notes for the same.