Sanguine Perhaps I should drop the "free" in the name altogether. It deteriorates the perceived value, while in fact you get a very high quality service.
I would not drop "free". It could be marketed several different ways. (Free can mean "freedom" as well as "free beer" after all.)
You might consider providing more information on your page, where you explain what you offer, it's limits and compare it to a self-hosted solution (Cons and Pros), and later, as I said earlier, provide "pro" versions of your hosting with less limits.
And I am glad you are not shutting down. You could provide a donate option at least ?
Oh, and also, don't stop developing just because you want to wait until flarum is more mature. Decide what you want to offer commercially, and build the systems for it so you can launch it at the right time ?
I am sure your framework could be used for any number of applications later on, especially if you add/have cloud capabilities for it.