I agree a light isn't needed nor a compass. Pretty useless if you need to see what your doing with the tool your light is attached to.
Can't talk about other people, but what I never ever use on MTs or knives: files, bottle openers and corkscrews... the latter ones look especially ugly, in my opinion My ideal MT would have a small blade, scissors, a flathead & a philips screwdriver (one of each), tweezers, something... with a pointed-looking... nail-like or sth (I often need such stuff) and of course, a keyring attachment of some sort.