Ermz have you ever tried really really extreme low passing?
I know you mentioned 7khz but I was scrounging around for mixing info and saw Dan Korneff, who works with Bendeth and I believe does most of his guitars, mention that he typically low passes at 5-6khz, I tried going as low as that and I can't say I miss any of the crap at all up there, although it does seem really extreme to be doing away with half your frequency spectrum.