Freakazoid

Im not sure if it is foss (have to check) but Soul Browser is my favorite. Packed with features and highly customizable, most if not all of your requirements are possible within this browser.

Did you try to switch to another instance?

And could Grayjay be another alternative to freetube?

(Edited, typo)

Morn was a funny character even tho he was mostly seen in the background. I vaguely remember him being the star in one episode but can't remember if that's true or my mind desided to made that-one up.