There's no reason not too, unless the blank/pariah gene messes with any of the organs, but that seems very unlikely.
Well Pariahs have no direct effect on normal people, but beings that are "soulless" generate a feeling of unease. In one of the Heresy books (Eisenstien...?) it talks about thier cooperation with Silent sisters. While they didn't do
anything to the Space Marines directly, the Space Marines didn't really feel comfortable around them.
Aaaaand of course the librarians would throw a fit
Crozius Arcanum: Because nothing delivers the word of the Emperor like blunt trauma to the head. (Of course....a power fist helps too XD)
Arkio was framed
Space marine lore: http://wh40k.lexicanum.com/wiki
Horus!!! You threw off the Emperor's groove!!
Nope, not really.
Tycho is a big bag of suck wrapped up in shiny gold Nipple-Plate