They will ALWAYS bite the cage. Ive had 4 prairie dogs and all of them bit their cage. Its just a PD's nature to dig and burrow to expand their territory.
For the biter, when she bites, say NO! very loudly (or another noise that startles them) and immediately put her into a small solitary cage for about 10 minutes. (I use a carrier cage) The cage should have no food, water or blanket. DONT put her in if she is only being mad. Put her there ONLY if she tries to act on her anger (scratching and biting). They HATE being in isolation more than anything. Do this every time and hopefully she will learn. It worked for mine.
I dont have much knowledge on the other issues.
Good luck!