212man - a) is not a problem in the UK and we fly around on RPS or QNH outside the MATZ just like everyone else so b) is irrelevant.
Maybe we should all use QNE for landing, that way you never have to reset your altimeter from 1013
The instrument approach on QFE is usually to the same numbers eg 150' for helicopters on a PAR or 200' for ILS so you don't have to do maths whilst flying - generally safer all round I would say.
As for pressure error - unless you are at the airfield datum your altimeter could be many feet positive or negative before you take-off - decision height or MDH are well outside ground effect anyway