Linux

Don’t worry about swap, you’ll be fine unless you’re usually working with huge chunks of data like big 4k video files or something.

The firewall built into mint is the kernels included nftables the same one built into Debian and Ubuntu (I think, I don’t fw Ubuntu). It’s fine. Don’t touch it. When you need to mess with it you can figure out how to open ports or split routes or whatever really easy because there’s lots of documentation out there.

Putting everything in your home folder is fine. Programs will install automatically to /bin or /usr/bin or something like that and if you want them in your home directory you could make a ~/.bin/ directory and add it to your path and have your private programs there, but:

Stop using flatpaks or snaps unless it’s your only choice! You have a built in package manager with decades of testing and development behind it and a very capable team of maintainers who watch over the packages, use that instead! That’s why they say not to use the snap store, it’s a vector for using Joes Weird Program that no one has tried before and requires Joes Special Version of a normal system library.

Use your package manager.

You’re not at the point where you understand enough to do the stuff in the linux hardening guide without making decisions that unexpectedly cause you pain somehow. That’s not an insult, sometimes you just don’t recognize the “universal” symbols for engine oil as opposed to coolant and ruin your car by the side of the road because you just don’t know. You can learn that stuff later, but it’s best not to mess with it yet. Speaking of:

If you don’t have a backup solution setup and you haven’t recovered using it and aren’t periodically checking to make sure it’s still running right, turn off disk encryption. It’s much harder, sometimes impossible, to recover data off an encrypted disk. If you don’t have a backup and you don’t know how you’d access the files on the disk without booting the computer then turn disk encryption off.