Is my knuckle skin cracking a bad thing? Sometimes it bleeds.

Not really. Skin cracks when it gets dry, the same way leather does, especially in areas of high movement (such as knuckle joints). The most common cause of dry skin on the hands is frequent hand-washing, which is a good practice, but does dry your skin out. Get a good emollient hand lotion and apply it after each washing. If the problem persists, let a dermatologist sort it out.
Knuckles skin cracki. You mean the skin peels off? How many knuckles? All? Both hands? You do martial arts? Work hard with hands? Chemicals involved? If not swollen, not red, not painful, fingers move freely in all angles and are working well, and occasionally bleed, no problem. Keep them clean. Blood comes out, germs come in.