I was able to get 6.5" speakers to fit in the front for the RSX with no clearance issues at all with a little bit of dremel work.

#1 My question is whether or not i should use spacers so that the speakers are not rested on the sheet metal itself and cause vibrations.

#2 OR would using foam baffles be good enough (as i have no clearance issues) and it would protect the magnet from any harmful elements.

#3 OR would it be best to do both #1 and #2

You should put down two layers of dynamat between the sheet metal and your speakers..that would help with vibration..

M

yeah - i already opted to put down a layer of dynamatt between the speakers and sheet metal and didn't bother with the baffles.
I think a layer should be sufficient for it