PC version has special moves in vats like grand slam with shovel and back slash with knife.

Now in ps3 I dont see these options why is that? are they just not in PS3 or am I missing something.

I think you melee skill has to be 50 and above before you can preform those moves, I remember reading that on a load screen. Now If you do have 50 point in that skill and still don't have those options then there is indeed a problem.

Yes, this is true.