Regarding FM, it basically works fine now, but there are some strange issues with audio routing. Sometimes it works, sometimes it doesn't... and if it does not work, triggering some other kind of audio playback makes it work. That's probably a bug in the Blade's libaudio, and it likely doesn't only affect FM radio.
Also, ZTE's si4708 driver is a piece of crap. It's not only written in an odd style and with horrible formatting, but while cleaning it up a bit I already found two bugs - wrong band selection, and incorrect channel spacing mask. Both are fixed now. I also added an important missing feature, de-emphasis setup.This should improve audio quality a bit. Oh, and seeking should be faster now.
I have pushed all changes to the kernel and device repos.