Now gentlemen.... come on... the credit card companies are not the devil. Yes.... I work for a bank, but
not the credit card division of the bank.
Wytstang credit cards have there place and effective uses. I would not close the card if you have had it a long time.
Killr can explain that better than I can, it could mess with your credit score. However, I would pay it off if you can or do a balance transfer, if it makes since. Most companies will offer a balance transfer at 0% or a good rate. Just watch for processing fees do the math and make sure it makes since.
Credit cards are a good think IMO. The are convenient, great to use for on vacations... you need something to put tickets, hotels and rental cars on. You just have to make sure you pay it off when the bill comes! It's a way to conveniently to get an interest free loan for 28 days. I use mine for daily expenses and pay if off each month. It help increase your credit score when you use your credit wisely.
As far as USAA, my husband has been a member for a long time, he is very happy. I have mine where I work... go figure.

I hope this helps!