I am not a USAA Advisor, nor a USAA Employee. I am just a Member like you.
That said, the subject of Roth IRA's is too complex to give you a simple answer. This forum has Moderators whom are Financial Advisors whom may be better able to answer some your questions.
A key bit of advice that I can give you is that you should not withdraw any funds from your Roth IRA's without talking to a financial advisor first.
The best answer is YES you can withdraw fund from your Roth IRA with this key caveat:
Also the only real help I have for you are the following LINKS which should answer some of your questions.
1. USAA - Financial Advice Blog (maybe you could post your question there)
2. IRS - Roth IRAs**(External Link)
3. IRS - Publication 970 - Chapter 9 - Education Exception **(External Link)
4. Using Roth IRA To Pay For College **(External Link)
5. Using a Roth IRA for College Tuition **(External Link)
I hope I have helped you.