What I always do if something like that happens, is calmly exit the game, go to my c drive=fh=terrains, then remove the map file that crashed, log back on, and my character will be in a safe non-glitchy black zone XD. Then I just go to my home, and log out when I want... or continue playing for a while then log out.
Eventually when I want to go back in the map, I try flattening it in photoshop or something that edits the map files to fix it. This always help so that you don't have to delete your charrie! Hopefully you can figure out how to fix your map if this ever happens to you!
But I do love your idea, I would really like that button, even if you weren;t stuck and just wanted to go home fast before you started to save time!