Their API/role is very similar to the `forms` in standard Django. I agree with you that they handle too much stuff and that saving to the database has nothing to do in a serializer, just like it has nothing to do in a form. But I also think it's a very good choice to follow common Django practices, so that codebases stay somewhat consistent, and new users are able to understand the concepts very quickly.
Migrations are about data, not schema. You don't need migrations with a "schemaless" database at the beginning, but as soon as you have data you care about, you're gonna need to ensure some sort of consistency.
Did you take a look at the way gittip does this ? You basically donate to a twitter handle and its owner can 'claim' the account whenever they want. No money is actually transferred until the account is claimed. I don't know if it can be applied to artists/bands though.
I was also wondering: is there no transfer fees with paypal ? Don't they make small amounts transfer useless ?
And one last thing: is it not weird for bands/artists to suddenly receive money from people without being informed about the site and all that ?
It would probably be possible to make the extension use the system's installation of python if available instead of the one embedded with Sublime, but that would require some coding.
Nice! I just have one or two remarks about the UI: it is really annoying that when you click the text of an answer it closes it back, and the font is two small.
I've been using my Nexus 4 for one week now and I obviously love it. I think the feature that impressed me the most is the 'gesture typing', which compensates for my apparent inability to type correctly on a virtual keyboard. And it works surprisingly well in French too.
The Either type described in the first comment is also a Monad. They are more important in Haskell than just "when you need to write to a file..." and I don't think you can totally grasp the error handling method without understanding them.
Maybe you shouldn't write tests for a "prototype" that you're going to "throw away". Tests are (in my opinion) necessary, but TDD is a style of coding and you don't have to use it.