I like appimages personally.Find them useful when i have conflict of depencies in package manager.I don’t like snaps comparing to flatpak.Flatpak let u add custom repositories but not snaps ,canonical want to control from where u will install snap apps.

Well it’s require reverse engineer them,but knowing Facebook don’t expect anything good.

U need universal android debloater it works via adb and u can delete apps temporarily until factory reset,u can also delete a lot other Chinese spyware like msa daemon which sending tons of data from your phone.https://github.com/0x192/universal-android-debloater And yeah this apps always come preinstalled with any xiaomi phone for Facebook surveillance :)

Recently checked ,Ubuntu already removed more old version libllvm15 from their repo ,only new one available.But I am not recommended u to use brave browser they are lieing about privacy things,if u really need chromium engine and deleted bad things of google ,try ungoogled chromium :)