Yes...But make sure you wipe it first.

As long as you're clean, I don't see the problem. The only time you should trim/shave that area, is if you're planning on having it be a part of the action (ie, anal stimulation etc.) It's really up to you though. I'd imagine it's an awkward area to trim or shave.

I think most dudes have hairy butts. As marvel said, as long as it's clean, it doesn't matter.