The most important thing right now is probably making sure that there is a documentation of the old API we all agree on. The one you are using [1] seems like a good start.

[1] http://undoc.in

Did I miss something in their API, or was there absolutely no way to tell whether you had renamed a feed or not?

I might pitch in and help on this, I know I'll be looking for a replacement to Reader, might as well help build an api implementation