[@Eisenhorn]
Yeah it would, it'd wreak everything ever...or fizzle and automatically die. Yeah, oddly enough it mainly involved making changes which were actually quite obvious really - like the fact that the Forge worlds are so assbackwards when it comes to doing stuff, and even the Astartes aren't nearly as retarded when it comes to combat doctrine and recruiting. GeeDubs used to be pretty amazing with lore regarding most things though things recently have taken a downhill turn. Yeah, the PDF have always been downtrodden and otherwise just downright pathetic in all things - so we made them into an actual fighting force capable of ACTUALLY defending a world from attacks. I agree there, whiteshields should be terrible, I mean it's Joe and Jim the farmers from some backwards area - they haven't got a clue what a lasgun IS let alone how to use it. But overall the guard should be a competent and determined force.

SANITY IS FOR THE WEAK!!! But having sane members of a warband does help somewhat - stops the ceramite blender that is a berserker from charging into baneblades for example. Though yeah, that sniper is just scary powerful, like Tyranid biotoxins level scary. 

Average lifespan depends also on whether you are crucial to the plot or a named character... who apparently can survive being in the warp alone for multiple months... (Talking about the Ultramarines books by Graham MacNeil here.) But yeh.