If you "Place" a part or assembly with the right mouse button you get options to rotate your part/assembly. This is verry usefull.
I would realy like this option when i paste a part or assembly (rmc + copy & rmc + paste in an assembly is very fast) so i can place and orientate parts en assemblys close to there end position.
Further i would realy like this functionality added to the free move command.
As a Bonus it would be even better if the rotaton angles snap to 15 degree steps.