airosen

Well I received my brand new Shimano PD-M324 clipless pedals today from the post office. I paid my DUTY, and was on my way. I quickly installed the cleats on my shoes, pedals on my bike, and learned how to clip in/out. It took a bit of fidgeting, but I started to get the hang of it after a while. My first ride was delightfully uneventful (no 0 km/h falls! ) although I almost fell at a busy stop sign (of course in front of a lot of people). Luckily, my pedals were set very loose so my foot came out as I was about to topple over.
Anyway, I love clipless now! I guess I'll have to work on the muscles that pull up on my foot, for I'm used to just pushing down.
I've got some questions though.
After my first ride, I looked at the bottom of my shoe and saw that the black finish of the two bolts that hold the cleat was almost completely scraped off. It looked like the allen head was damaged a tiny bit. Is the head going to wear down so that I cannot adjust/remove the cleat? And if so, how would I remove the screw?
Also, what kind of maintenance must I do on my pedals? I greased the threads before I put them on my bike, but are there parts on the pedal that should be oiled/greased? And how do I clean the pedals if they get muddy? Is a hose fine?

Thanks!