I’ve never tried Bedrock myself, but was intrigued enough when I learned about it to read up. (So take my words with a huge grain of salt.) I believe that you have it right in your first point: you can run a kernel and drivers from, say, Debian stable while running cutting-edge rolling release userland applications from, say, Arch. And if you want a few slower-moving applications you can get those from, say, Ubuntu while still running the rest of your system as Debian and Arch. And if you need something really obscure that you can only find in a weird Gentoo overlay…
As to your second point, yeah, you can go with SystemD from wherever or OpenRC from Gentoo or Runit from Void or whatever else you want.
But really, I suggest you try out Bedrock in a VM and find out for yourself. If it works like you want it to, then go to town on your bare-metal install (after backing it up first, of course!).
The fricking hamburger menu on desktop applications. I don’t care if there’s an option to use it or even if it’s the default option as long as there’s a way to get a traditional menu bar. But when it’s the only option the designers can fuck right off. Monopoly and privacy aside, I’ll never use Chrome just because I have to use a stupid hamburger menu.
I completely understand why it’s used on mobile devices, and thus I get why it’s used for non-mobile devices. People who are used to it from mobile want it on the desktop. Or maybe your vertical screen space is limited and it lets you get back a line of space for other stuff. But it’s really just poorly re-creating the menu bar while requiring (at least) an additional click. When there’s no good reason for it, it just sucks. Give me an option to use it or not!