That's the good thing with open source. You can theoretically fork it and remove what prevents you from using Kate as root.

Sure. But the malaise of smug people taking decisions that are outside of the scope of the software is creeping into linux too. It is up to me decide what is secure, not them.

It's smug people telling other people what to do all the way down!

You dont have to use that software. Who even would? You're an adult, presumably, so use vim.

ed is the standard text editor.

Kate/Kwrite will ask to escalate to root if permissions are not sufficient. If it's not available to you, that's because your distro patched it out.

For ssh - sshpass.