Well as for FMOD doing its voodoo with Xine I haven't been able to reproduce what it was doing so I'll just chalk it up to "whatever" and move on. I had Xine going through FMOD with a ring buffer but it still had clicks between buffers that couldn't be completely eliminated, so I'm saying to heck with it for now and will just close the instance and let Xine open the device itself. I won't get spectrum data but I doubt anyone really cares about that while watching a movie anyway.
I wish I could help with your S4 problem but I've never worked with that chipset before. I do know that many chipsets will change the refresh rate for both outputs to 60Hz when composite/s-video out are enabled and there is squat you can do about it.
Oh hey btw have you given your frontend a name yet? I've seen talk around this section about your player but nobody has referred to it by name :)
Silverwolf 2 is plodding along as I find free time here and there so hopefully the ~3 month timeframe is still accurate. The thing that is really taking time right now is completely re-engineering the skinning and UI. Alot of the backend guts will just be code from 1.x ported to Qt4.