In <img src="/ubbthreads/images/graemlins/beyond.gif" alt="" /> if you want to eat, you have to sleep, and if you want to sleep, you have to eat.
So you can't just eat a chuck of meat to heal you like in DD.
If you are low on potions, try to runaway and find a quiet spot to sleep. (hopefully you have the bedrol)
For the degrade quality - I'm not sure (would like to know this myself), but I think it has to do with how fast the item's duribility goes down <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />
I have a sword which have no degrade quality (??), it's duribility does not go down - stays at 41 irrelevent on how much I use it.
<img src="/ubbthreads/images/graemlins/alien.gif" alt="" />