If you execute on this plan, you are probably an unlicensed MSB. If you don't know what that means, don't execute on this plan until you do.

What's the process to becoming a licensed MSB? Is it possible to test this method out, w/out becoming licensed to make sure that it can in effect bring in revenue?

I'm planning on doing a proof of concept - less than $100 a day.

IANAL but...

"the term “unlicensed money transmitting business” means a money transmitting business which affects interstate or foreign commerce in any manner or degree".

If you keep your trades to people within your state, I don't see how you'd be breaking the law here.

I believe you to have a much narrower interpretation of interstate commerce than Uncle Sam does, but be that as it may, there are (at least) four parties to the transaction: you, your counterparty, your bank, and Coinbase. Do you think it is likely that all of them are in California and only California?

You're also picking at one thread of a regulatory tapestry. Even if you are successful, there are a lot more threads.

Have a look at Wickard v. Filburn