1. I don't have any server-side logic whatsoever. All requests are made through Facebook.

2. I did some consulting work early on as well, but I would say I spent at least 6 months of solid development on the app.

Facebook should have no reason to block Current. I don't block their ads, and I've actually found that users of my app end up being more engaged with Facebook. Current makes using Facebook a more positive experience, and that's valuable to them as well. It's also very difficult for them to reliably detect users from my app.