I tried a FARP before i figured out how to Vertical Land, it didnt go well but mostly cause I just didn't know what I was doing. I've since landed on a road, and in the middle of no where. In the ME you can set start location to: Air, Ramp, Ramp Hot, Runway, Ground, Ground Hot.
Probably slightly worse, but, I couldn't tell you the FPS performance for the mirage when it was early access cause I wasn't playing DCS at that time. This thing has more stuff, its more on par with the A-10 avionics-wise, so I would expect it to be slightly worse.