You don't have to do that in Linux. If an application is giving you a problem you can stop the app without rebooting the whole system.

For example, if you started vi from the console before you ran into problems, you could type CTRL-Z to stop the job and send it to the background.

If you're in an X session, like in Gnome, if things get out of control the worst you should ever have to do is type CTRL-ALT-BACKSPACE. That will crash X and send you back to the command line, where you can start over.

vim - even though i don't use 99% of it's features, once you get the hang of it, it roxx

I use KDE exclusively as my GUI and I use Kate as my text editor. I seldom edit text or configuration files while in console mode unless I am purposely working in console mode. When in console mode I grudgingly use vim and midnight commander. None of the console text editors satisfy my concept of usability. That is only my opinion, of course.

As far as using Kate with root privileges, which often is necessary to edit system configuration files, there is a short how-to that explains how to do this in KDE.

Just a note about your being unable to terminate your vi session, next time consider toggling to a different console session. From there, using the ps ax command, you can identify and then kill the vi session.