Not sure why reflexes life steal and pw are un your skill set
What build are you suggesting for the endgame rogue?
Also why damage rings which can be easily trumped by mord skill rings
Which Mordris rings are you talking about? Mord rings are pretty crappy for raid bosses since none of them add to two dps skills. For necro It would be much better to equip 2 godly event Qs rings, or a godly qs ring with either type of necro ring. Only one rogue should have 50 rend so what do u recommend to all the other rogues present at a raid?
For Mordris/hrung/DL bosses the mord rings don't even come close to poison dmg rings, necro rings or event Qs rings. Hrung rings trump mord rings on 200 as well, heck even 50 dmg agg rings are better on that boss. Poison weap is far better than rend on mord.
To the OP, don't forget about attack. With boss resist elemental dmg will hardly raise your hits and for rondel rogues with blood sets, most the dmg you do comes from divine dmg/poison/poison weap (if you use) So it's generally better to use Attack braces/helm/rings over dmg ones. With full dex build I can get up to 815 unresisted dmg with poison weap and 7.7k attack on Attack lix, and have never lost a Mord kill with this build. Now a days I use even dex/str since dex is best for Snorri/mord/hrung and str is best for adds/200 event.
Full str is the best dps for necro, full dex is best for Mordris however even stats is my favorite