Hey dude - full of good questions today!
A while back I did report some lipsync issues with ROHQ here on one of the threads, as did a couple of others. A quick fix was to use ROStd which worked fine. I haven't tried ROHQ (in earnest) ages now, but will start to fiddle again now that my HTPC is back together again and most things reloaded. Haswell, my 8 month old is taking up most of my fettling time at the moment, it's going slowly!
In terms of stutter, I haven't experienced much with live TV. I do make sure that my Display is set to 50Hz as a default. MC doesn't yet change refresh rate automatically for live tv (MadVR might I suppose). Hopefully one day.
I did watch about 10 minutes of Cbeebies yesterday with ROHQ and it seemed fine although not the best to judge lipsync with! I had to dial down MadVR slightly from the default because of a weakish graphics card (GT430), MadVR was reporting some dropped frames. I enabled Exclusive mode and increased some of the buffers and it was fine after.
ROStd has been rock-solid for me though.
Keep up the questions! More traffic in the TV forum can only be a good thing (although might distract Yaobing from coding though!)
SBR