Your home partition can be anywhere, I would recommend copying the files to your new drive and adding a /home mountpoint flag in the kde partition manager.
See above
The newest hotness is something like btrfs and pooling drives together under the same mountpoint. Otherwise just do what you were planning, a big root partition and a 1TiB home partition.
I guess my issue is that these are production machines that aren’t really meant to be mutated and I’m generally just pulling diagnostic data off of. Often I’m ssh’d in to a hub machine and jumping in to edge devices, so I couldn’t run ssh kitten if I wanted to. I think I’m probably an edge case, but it is very frustrating.
Not sure if I totally grok what you’re asking but try Ctrl+v to enter visual block mode or whatever it’s called, navigate down to the line you want to go through, hit Shift+I, type in your junk, then hit escape.
Sounds like it’s not the game for you. Overcoming environmental challenges is kind of the name of the game, and if the baseline “cold bad but fire hot” thing isn’t something you enjoy then I’m not sure you would enjoy trying to navigate any of the main story areas in the game.