"I get the same joy from coding that a painter gets from painting. A painter that can paint what, when, how, why and where they want is likely happy. A painter that has to paint what other people want on a schedule is often just struggling to pay the rent. They develop a toxic relationship with their art, and that's sad." Love this quote Pete!
Same - for most of us, the technical execution is the easy part. Whenever I have an idea nowadays, I try to figure out a couple distribution points and also get some early market validation before getting started. Read more about the Lean Methodology :)
Was pretty much all I need to get started (I'm using one of their third party wrapping for .NET)
I guess it might get slightly more complicated if you are doing recurring billing or customers but their standard template should be sufficient for your needs at this stage. I pretty much took this example: