I finally took my car for a run the other day, after getting some work done on her. After pushing up past 60 I noticed some odd vibrations. Nothing serious but you could definetly feel them. I noticed them along the floorboard and along the door frame.
Since this is my first RX7 I just wanted to ask if that's normal or if I should check something.

Thanks!

 

Vibrations are never normal. The first thing to check is that all of the wheels are balanced properly.

 

What work did "she" have performed?
Anything involving driveshaft or running gear?

 

Like said before, make sure your wheels are balanced. And be sure they aren't bent either. Then check the drive shaft U joints. If those check out, maybe it's a worn out tie rod end or loose strut.