A guns fight is a significant reason of UCAVs.
A plane that can pull 10-15 Gs, or more, will have the advantage in a guns-only fight.
With missiles, it doesn’t matter so much.
The problem is situational awareness for the “pilot” sitting in a trailer. He currently can’t swivel his head to track the target, so they’ll probably have to put a gimble inside the cockpit with binocular vision.
I could hypothesize a 'cockpit' that rivaled cost of the F22 it is to substitute for. Actually, lots of them.
Also, unless it is pretty much like a full scale simulator - the 'pilot' will have a heck of a time dealing with a 3-D battle (currently, they are concentrated on a fixed target or a zone; not looking for gomer at the six...hun in the sun...etc.).
If you want to go all Sara Conner, you might think about a man-less battle with AI providing discretion to the platforms. In which case I'd invest heavily in anti-unmanned platform defenses.
I agree that guns will have a large role in unmanned development, the vehicle is cheap enough to put in close and a missile hanging on the wing basically doubles the cost.
Jamming, misdirection, and EMP are the true weapons of the future (if we're willing to address them) unless there's a wholesale reversion to wire cables and vacuum tubes. Oh, and hand cranked telephones with miles of wire.
Or, maybe I'm just old fashioned.