If I'm not mistaken, the Army Nurse Corps has it's own recruiters. Your husband would need to speak to them for specific advice. You can find more information about the Nurse Corps at the following link: http://www.goarmy.com/amedd/nurse.html
I can tell you that ALL married service members, not just E5 and up and stated above, receive an allowance for housing. If you live on post, all of the housing allowance will go to pay for your post housing. The amount of BAH given is based on rank and location. Depending on the amount and the area, there are times when it pays to live off post.
For enlisted, service contracts are 8 years. You can break that up into several different options. I served 6 years in the Reserves and 2 in the Ready Reserve. Active contracts can very. I believe the minimum for an Active contract is currently 4 with the remainder to be served in the IRR, Reserves or National Guard.
Loan repayment programs change often depending on what is being offered at the time. I was offered a repayment of $20,000 when I joined. I had no student loan debt, so I asked for other things. I have seen it go as high as $40,000 repayment. Like I said, it depends on what is being offered to specific jobs at the time. A recruiter would better answer that question.
How often you move will really depend on the needs of the branch of service. I know several Army nurses. A few of them move often. A few of them have been stationed at the same hospitals for 4 or 5 years.
Do you have any other questions we can answer for you?