Regarding the yt screen things, that came at same time as the time delays; I did figure out how to push around the AD that plays previous to any topic video.
First, as the AD video goes thru it's first few seconds, I press on the 3 dots (smart phone) that brings little menu, starting with 'Settings'.
When 'settings' is pressed, the AD pauses, but then a press on the phone's 'BACK' key and the AD resumes...this time showing in a little window, at bottom.
Pressing the 'PLAY >' then moves that.little screen window, up to expand to regular sized video window...
At that point there is some variation, but generally goes to 'SKIP' (the AD), sometimes a count-down a few seconds, or it will say 'Video plays after AD'. Pressing the 'SKIP' or waiting the couple seconds, will get your video started, and in the big window.
Most always works....although sometimes it's a video that got pulled (showing the '!').