For keybinds, there is the project Toshy which redirects keys to emulate Mac bindings. It has some issues but works pretty well in my experience

Android is NOT open source. AOSP is, but the android distributions you get on a retail phone add proprietary and closed source features atop AOSP. It is at best open-core but even that is questionable given the release cadence of AOSP

The Mac ecosystem has its own set of tooling for this. It uses Apple’s Rosetta 2 for x86 to ARM translation, and their Game Porting Toolkit (GPTK) for DX12 to Metal (Apple’s proprietary graphics API) translation.

(Should note that Asahi doesn’t have full support for M4 Macs yet so I’m assuming they’re on MacOS)

That use case makes it sound like you’re looking for a vector editor, like Krita

This is not what libadwaita is. Libadwaita is their modern unified library for the adwaita theme

That’s not the case for the newer open source drivers from nvidia. They’re only compatible with the last few generations of cards but they’re performant and the only feature they lack is CUDA to my knowledge. Not talking nouveau here

You can make custom images of this with some software called BlueBuild. I base mine off of the Secure lue project then tweak it for my needs