Hi there. I'm not much of an expert on GUIs either, but it's something I've thought about more often recently, so I'm gonna chime in a bit.
On the subject of Browsers, I mostly jumped ship from Firefox when they broke most of their extensions a few years ago. I'm using Vivaldi nowadays, which is being developed by former Opera people. I'm mentioning this because of an old gripe I have with the UI of most browsers (and Vivaldi is not perfect in that regard, just better than others I've tried): most websites have quite a lot of dead space to left and right of their content. This is not necessarily a bad thing, I'm guessing it is like this for compatibility reasons. Yet all browsers I'm aware of put the majority of their UI on the top and bottom of the website by default, decreasing how much content is visible at any time, while the left and right of the screen go unused. (I suppose that is less of a problem if you are browsing windowed, but I do most of my browsing full screen.) Vivaldi at least lets me put the tab bar on the left, freeing up some of that sparse vertical space and making use of the huge amount of horizontal space (you can also turn off the tab close button, and it supports mouse gestures out of the box).
Ideally I'd want something like an old RTS, where everything is to the left of the main view, but I don't think that exists yet.
That wheel interface you proposed looks very interesting and I'm amazed someone whipped up a proof of concept already. I could see myself using that.