All of this is fairly reasonable for the kind of project it is. Sounds like you and those users don't understand what signing up at any site really means and you've been so separated by the front end, you be have no ability to show grace when basically using a website for free hosted and manages by free people what takes money donated by others?
Why is this anyone else's fault but you? You've gotten spoiled. Maybe everything isn't for you if you cannot even do the bare minimum to participate?