Light editing meant, less on GPU extensive effects and transitions. I am a professional editor myself, my first rig was core2duo e7500 with 2 GB ram and on board graphics. I use Premiere (never used a Mac). Then i upgraded to i5 and 8 GB ram and then to the current config you can see in my signature. So the point is, your configuration is OK, but soon enough you will realize that what you can achieve with this config is very limited to what you can if you have a better system. Powerdirector seems fine for you but you will still be better off with more RAM.