I don’t know why there would be a login issue with Firefox unless you have some funky browser settings or extensions interfering somehow. I use it on Linux and just logged into the Web View. 
Using Edge or another Chromium-based browser is probably the answer here.
No, but it’s what Wyze officially supports for Web View. Like I said, I can log into Web View using Firefox and see most of my cameras without any significant problem, but I’ve never seen any of my Cam OGs connect in Web View using Firefox. They work as expected when I use Chrome.
Not all WebKit-based browsers, apparently:
I’m not sure what the issue is there. I kind of expect it with surf, because that’s such a minimalist browser (and uses WebKitGTK, which I guess technically isn’t the same as WebKit, but I thought it was worth trying). GNOME Web isn’t quite so bare-bones, but it lacks the settings flexibility and features of more popular browsers, so I’m not too surprised that it also failed.
I’ve played with that some on Linux and Windows but have never adopted it full time and tend to forget about it. Good call! 