A number of posts here mention, "Belt Factories." I am becoming a bit suspicious of the place my daughter is at. There are a lot of wonderful things about it, but they really do seem to advance kids rather quickly and sometimes before they are able to do forms without following others. She is in TKD.

How long should advancement from one belt to the next normally take?  

How does one learn exactly what is being watched for during tests?
Are tests and passing requirements fairly standard Or fairly subjective?
Are there different standards for advancement for children than adults (they seem more lenient with children).
Once "invited" to test, kids seem not to fail. Is this the red flag I think it is?

Sorry about the long list of questions - I'm trying to make my thoughts/concerns clear. If you were choosing a new Dojo, what would the red flags you would look for and avoid be?