Thats a bugger about the quit key not working on the 68000.
Not really, you can get a 68010 typically for under $10. Unless you have an a600 or minimig 1.1. Well, you can still get one, just won't fit

Piru is correct about the VBR, I remember reading about requiring that register specifically for the exit key. His description of how its used is more technical than the whdload docs which is nice.
I don't see why you are you are using such an old version of whdload anyway? I'm sure I have at least 17. Something.
Perhaps it allows exit key to be used on some games, I know a lot do exit on my minimig.