Dermaroller after FUE. I want to use it on my corner temple areas (which is not part of my recipient area) is this ok?

You can certainly use the dermroller in other areas other than where you were grafted.  There isn't any data on whether you can use it in the recipient area.  

It is best to contact your surgeon for post surgery care since all doctors have slightly different instructions.

Derma Roller on areas not transplanted is perfectly fine, and it's common for people to use it in that way to stimulate hair growth. It's definitely worth a try to see if it has any positive effects for you.