If you already fed it to him, I wouldn't worry about it. Symptoms would be similar to epilepsy from what I've heard, and would become more and more severe until the snake expires. I would expect they would show up within a few days. If you don't have mouse/rat bait set out, there probably won't be a problem.
Regarding the shed, I usually soak a towel in warm water, wrap the snake up in it, and sit and watch tv holding the snake for as long as he will tolerate it. Eventually the snake will start trying to get out of the towel. I'll put a little pressure where the stuck shed is while the snake is trying to get out of the towel, letting him do the work. But, like others have said, its really not a big deal to just leave it until the next shed.
Steve