A few questions on moving to Ecuador

My friend and I are both 23 and we are looking to move to Ecuador for at least 6 months. We decided on Ecuador because I've only heard great things about it. The people are welcoming and very nice, the weather is beautiful year round, they use the USD, it's cheap, etc.

I'll just list then questions below.

1. I know they use the USD and I have a USAA banking account. Will I be able to use my debit card on purchases and withdraw money from ATMs? Or will I have to sign up for a bank there and transfer money when I need it?

2. How should I go about using a phone there? I'm going to be selling the phone I have now for one with better battery life. So should I buy a phone in the states before going or wait until I'm there?

If you are planning on buying a smart phone then I would do that in the US and get it unlocked. 
If it is just a phone that makes calls you should be fine picking that up here.  As far as bank accounts you can use your ATM card here with a major cc logo at logo ATMs for a fee.  if you plan on living here you can open a bank account with a valid visa (not including the 90 days tourist visa).

Mike