I've mentioned this in another thread about the Mrd accuracy issue and going for a drk build is NOT the answer, all you are doing is weakening every good aspect of the Marauder at the cost of nearly useless absorb spells.
Mrd has awful affinity toward any of the mage skills so you will be unable to use them effectively, you are better off just letting a real THM absorb, then transfer the effects to you with initiation, and thats the ONLY way.
PIE is a useless stat, keep it at zero for every class, it has no effect on sticking power, magic acc, magic dmg, or anything at all really, its totally broken. See below for detailed and extensive parser results on PIE testing over multiple classes. As well as testing on other stats if you don't mind a good read.

http://ffxiv.zam.com/forum.html?foru...564&howmany=50

So in short, MRD/THM.. no, just no.