It's pretty good. A 100% crop on a 200mm lens is only JUST enough resolution and I think you've done a good job.
The limb brightening is an artefact of the sharpening, and there's not much you can do about it unless you get tricky with masking out the limb when you do your sharpening.
I show that technique in my article
How to create a colour saturated moon photo.
The brightness of the blue sky doesn't help either, it'd be easier to take when it's against black sky so you can clip the sky levels back to 0 or pretty close to it.