I started out on clips and straps and can never understand why anyone would not want to switch to clipless pedals. If I were you, I would put them on as soon as possible in order to begin learning how to get in and out of them. It will take a little time to get used to them, but you will be better off in almost all situations because you are clipped in. Rich is right on all counts and, as I said, there is a learning curve associated. But find a park and start clipping in and out and you'll be great in no time.
As for mud clearance, eggbeaters are often suggested because of their open design. I have yet to ride them in mud, but it makes sense that they would shed it quickly.