a) does MorphOS do something to DH0: or something in NVRAM or PRAM (I've cleared both) that does not allow my restore discs to work?
b) what blind keyboard presses can I make during a fresh install of MorphOS so the proper video adapter gets chosen so I can see what's on the friggin' screen?
a) No, DH0 is just a normal HFS partition. As for NVRAM/PRAM, MorphOS never touches these. You might want to erase them (cmd+alt+p+r afair) in case you're having odd hw problems - it sometimes helps.
b) If the timings go bad, try holding the ctrl key while booting - this forces 1024x768x60Hz which most (all?) monitors will display.