When your knuckles are cut up use antiseptic cream and bandage them up. If you leave cuts open they will dryout and keep on cracking. I wish I did that years ago. I have a 7 yr old scar on my left hand the size of a small coin, it splits open every winter, looks gross and stings like a bitch.

Look after your hands, you wont get another pair.
Conditioning is good, but if you draw blood your not conditioning your just messing them up.

Also, when your knuckles are raw from heavy bag work, its a great time to practice your palm-heel and finger strikes.

Bigger bones > smaller bones. If it's a real fight, I use my elbows and knees quite a bit.