Oh, you mentioned you don’t want to keep a backup of the entire drive. That is fine, but absolutely back it up before starting the install.

I would just boot a live Linux image and dd the entire device file onto some sort of storage. That way you can get a bit for bit copy of the drive that you can make it how it was before you touched it. When all is well, then you can ditch the backup. It wouldn’t be a bad idea to keep if the stuff is important. Storage devices do fail.

Yes.

To do this, open a terminal, and do this:

sudo apt search ntfs

It will be called something like ntfs-progs or ntfs-fuse or both.

Then:

sudo apt install PKG1 PKG2

Alternatively, the synaptic package tool has a nice GUI

You could leave the Windows installation and not dual boot. Linux can read NTFS volumes. You will probably have to install ntfsprogs or whatever it’s called.

A swap partition is akin to the page file on Windows. The kernel will use it to move memory pages it doesn’t anticipate using in the near future to it so it can use that RAM for other things. It will also use it in a pinch when there isn’t enough RAM on the system. It isn’t strictly necessary, but it can prevent programs from crashing at a huge performance penalty. It is necessary if you want to use sleep or hibernate or whatever it’s called when it is powered off physically but resumes what you were doing instead of booting when you power it back on. That takes as much swap as you have RAM at minimum. If you want that, a good rule of thumb is 1.5 times physical RAM.

I have servers I administer for my job that have over 100GB of RAM with very little swap, like 4GB. The applications and machine are tuned and sized so the physical RAM is at ~85% and swap is barely used. The swap is mainly for non application stuff like IDS agent, backup agent, monitoring agent, etc.

If swap becomes a problem, you can adjust the kernel vm.swappiness parameter as needed. It might take some trial and error to get it right.

Source: I’ve been working with Linux professionally for almost 20 years now.

There are no guarantees. Life is just like a hold em game. The only thing you can do is make good decisions based on the information available. Sometimes a dumbass with 2-7 off keeps calling your bet when you hold AA and catches two pair on the turn and river. The only thing you can do is not get tilted and keep making smart plays. Variance is a massive asshole. Eventually you will come out ahead.