I don't think Kirito is supposed to be the best sword fighter in the world. Suguha can beat him in kendo.
He was the best in a small pool in SAO.
In ALO and GGO, he has the advantage of having played VR games more than basically anyone in the world and completely being used to VR combat.

Also, Kirito is a dual wielder. He never beats anyone good with one sword through pure skill.

Regarding the villain... Dude, he was executing a plan to sneak into people's rooms and murder them in their "sleep". Of course is freaking psychotic.

I wish they had made the scene with Sinon waking up a little more tense. Instead they're playing soothing music. That situation would be utterly terrifying.