My answer for #2 is I have never personally had a problem with Linux on a laptop. Everything works as intended. The only funny thing was when I switched to Arch Linux took a little bit of work to get games to use my Nvidia GPU instead of the integrated one in my CPU. But that was maybe 30 minutes of googling and installing stuff off the AUR. When I ran pop_os it worked right out of the box. I believe pop has all of the Nvidia stuff installed and on Arch I just had to figure out what I needed. That problem was just from lack of experience.
My answer for #3 is I don’t know but I’ve had fun testing different software out to find something that suits me. I want to say way back in the day Ubuntu had a bunch of stuff pre installed. But that was probably 2007 when I last used Ubuntu. On Arch you can just use the discover store to find stuff. If you can’t find it there it’s in the AUR.
#4 rooting on Linux isn’t like rooting on Android. Android is built off Linux so to have “root” access is just like having administrator access or whatever on Windows. Android phones are more locked down so it’s usually a pain to root (the manufacturer don’t really want you to do it). On your own Linux computer you just use root access. For example on Arch in the terminal to do a full system update you have to use root access so you type “sudo pacman -Syu” in the terminal then it asks you for the sudo password or root password that you yourself setup on install. Sudo is the command that says hey I want to do this no questions asked.
#5 it’s Linux you can do whatever you want. You can go through and destroy the entire os if you want.
I’m coming on a year being full time on Linux so that’s about the best I can do answering your questions. I’m sure other people will explain stuff better. Good luck!