Automate registration and instantiation on Amazon EC2

Background:

I created an application that works well on an EC2 instance.
I want my friends to use this application too, but they are not very computer savvy.

Question:

• How can I facilitate installation and use?
  and. They will not use it if they need to know what an instance, AMI, and all is.
  b. Everyone must have their own credit card billed to AWS.
  with. I can provide .rpm to make the application install silently :)

• If I decide to sell my product after a while, how can I do it?