There's too many similarities between Mass Effect and Babylon 5 for it to be a coincidence. Just like how there are too many similarities between Dragon Age and Warhammer for that to be a coincidence.
And yet, I seem to have missed them all.
(which isn't to say that most things in DA have been lifted from somewhere else - but WH? WTH?)
Aspects of it (the warp fade and the Templars of Sigmar seeking out unsanctioned mages, practicing outside the Colleges of Magic Circles) because the untrained mind may attract the attention of warp fade entities, but my first thought when watching the cutscenes was Peter Jackson
As you said, a mix of some old, some borrowed and some new bits here and there.
Warhammer is pretty clearly tracable to Michael Moorc.o.ck.anyway. Chaos lords, the 8 arrow logo, corruption. Everybody steals from everybody esle.