1-Android allows side loading of apps from outside the store without much hassle

2-Android 12 should have a toggle that completely disables the microphone (however don't recall it doing so for the GPS, for that you'll have to rely solely on the permission management)

3-It can be achieved without root through either adblocker apps or custom/Private DNS servers

4-That's not possible without root and for a good chunk of modern apps it doesn't work due to stronger payment checks (not to mention this sort of behavior is not condoned)

5-that depends on what exactly you're trying to do, Samsung devices are in general quite customizable and certain apps may be able to complement that

6-if you mean using Google alternatives to apps and blocking most Google tracking domains that's feasible

As for the bootloader unlocking, the Android community tends to simply not bother with devices that ship with non-unlockable bootlooader, so unlock exploits are quite rare