I like the flying saucer chinchilla wheels best. You can find them at:
http://www.chin-chillas.com/ {Meadowbrook Chinchillas} Dr. Marty Hull on that site is the inventor of the flying saucer chinchilla wheel. (We have 6.)
Usually, a chin will not bite with out reason or before giving several warnings ... of course you have to know what the warnings are to know what they mean.
1) They try to run away/hide from you.
2) They will stand and fuss at you.
3) They will try to push your hand away from them with their paws.
4) Females (not all but some) will often use the one defence they have in the wild to protect themselves and their kits ... they spray you with urine ... beware, they are VERY ACCURATE up to about 7 feet.
5) They nip you firmly, but not breaking the skin. (Some will skip this step because they figure you haven't listened up to now, so why bother.)
6) They take a nice hard bite, usually to the bone.
A chin will bite if afraid, hurt or cornered. You and your home are 'new' to him, you would not instantly trust a stranger, don't expect your chin to do so.
Keep in mind they are only protecting themselves ... Probably the same as you would do in a strange place, being what you feel is treating being done by
a giant the size of a house! We often forget to consider the other point of view and how we would react under the same circumstances.
Sounds like you are making some very good progress. Eating out of your hand is an honor given to you by the chin to show the beginning of trust and bonding.
Her going to the top of the cage (closer to you) and looking out is a "please come talk to me or play with me" gesture by your chin.
Even if you do not have much time, please, at least give her a soft. "Hi there!" when you wake up or come into the room and a "Bye, see you later!", when you are leaving. This lets them know that they are being noticed and that you care enough to make sure you speak to them.
Oh, always wash your hands and face before handling or touching your chin ... their eyesite is not that great, but their nose is! If they smell anything that smells like food, they will probably try to take a nibble to see what it tastes like.
Also, never confuse love nibbles with a defencive bite.
Jo Ann