Going to have to disagree with the 1st part. It's not that difficult to get a Money Transmitter License in some locations. Expensive perhaps depending on if you are actually making any money. Time consuming definitely in some areas. But even in NYS it not hard. It's just forms you have to fill out and records you have to keep. AND if you are actually making money running it as a business these are records you would have to keep anyway.
The bold is the part I was trying to get at because most open-source projects don't make a ton of money, even with donations.