A:AnswerIt has built in graphics which are usually not that great for gaming, to be honest the 12gb of RAM would do more than the integrated graphics. But now for adding your own graphics card I do not know if that is possible for one if not both of two reasons:
1) the case may not be big enough/ have an opening for a gpu addition
2) the motherboard may not have room/opening for a gpu
Your best bet is to go to your local bat buy and talk to th Geek Squad there to see if it is a possibility!
Hope this has helped!
A:AnswerIt does not matter if you do it before the first power on or not. There are guides on how to obtain the product key so you can reactivate it on a new device ( in your case a new drive ) but I highly suggest that if you have not had experience in these processes that you spend the couple bucks that the Geek Squad charges if you don't have a plan with them and just have them transfer it over, it's less risk and easier to do!
Hope this has helped!