> actually makes for a better experience to download and then view them.

Can you specify how? I was doing this when I didn't have enough RAM for the Youtube player with latest Firefox and it's not what I personally felt. The current player has size options (larger or full-screen), annotations and comments can be disabled (e.g. with Adblock lists). In the end it's always having the video canvas in front of your eyes. Maybe integration with a tiling WM?

> I'd imagine it could even be automated trivially, by calling youtube-dl via a browser plugin, or by writing a script to pass YouTube URLs to with a simple GUI thrown together in FLTK or TCL/TK.

Existing means for VLC integration aren't that bad either.