There's FFshare and FFmpeg Media Encoder. Not the prettiest, but it'll run ffmpeg and you can pass pretty much whatever options you want, ideal for power users.

I don't have an answer for you unfortunately but I gotta say thanks for mentioning LosslessCut. I've been using video-trimmer for quickly clipping stuff from long videos and it's had a lot of issues for me, no idea how losslesscut slipped past my radar. Gonna give it a try when i get home :D