Clearly they were seen as a real threat if there was a resistance hiding from them and trying to stop them.
Skills with a staff doesn't automatically = skills with a lightsaber.
I don't see Ren as having tons and tons of fighting experience, but the fact is, he has SOME experience with both the force and a lightsaber, and that's more than Rey can say. By that point, if you go off the timeline stated in the film, Kylo had started training in the ways of the force YEARS prior to the start of the film.
As far as the lightsaber, there was no indication she got any HP from it during the fight. In ANH, we clearly heard Obi Wan encouraging Luke.