shaggy sheep
you should be on the vasi/papi for all landings except when you are actively avoiding wake turbulence or practicing ''obstacle'' landings.
if you are worried about losing your engine and crashing into surrounding houses, you must ask yourself:
is this airport a safe airport ? perhaps I should fly somewhere else.
and, what will you do if you are flying an ILS and lose your engine?
being on instruments does not guarantee you won't lose your engine.
if you are always high on the VASI/PAPI, you will have more difficulty judging your flare and you will have a higher rate of descent.
a pilot has many tools at his disposal. different approaches for different conditions...but saying that VASI is for instrument flying, or that it is UNPROFESSIONAL to be on VASI is just wrong.
a three degree glideslope works best for most types of planes. and variations, while possible, should be done for a reason.
and if your reason is losing an engine in a convenient position like downwind abeam the numbers, what are you going to do at some other point?
do you takeoff and circle the field to cruise altitude or do you takeoff and , after clearing obstacles, proceed on course?
the idea that you should be alert and know what to do if you lose an engine is a good one...to only make approaches that can be salvaged if the engine quits may just be nuts.