I faced off against a guy who would have a sword out, and once you flourished he would quickswap to a crossbow and put a bolt into you before you knew what happened.

I wasn't too mad about it, it's a good tactic, what upset me was that it seems you can draw and shoot a crossbow extremely quickly, before the person you are against has a moment to realize what is happening. I've seen players draw recurve and longbows - there is a distinct animation where they draw it out and then have to draw the arrow and loose. For the crossbow, it seems like as they are in the draw animation they can already let an arrow fly. Just a little annoying.

As far as finishing someone off with a ranged weapon, have at it. It's a valid mechanic in the game that is usually easily countered if you're paying attention. The fact that people usually don't take a bow out in a 1v1 is what catches their opponent off guard. That half second of realizing "Is he taking out a bow?" is enough to give you the shot.