29 Shadow Priest Guide - Patch 6.0.3

[Atherburst]

Bonus armor was removed from cloth defiler's gear. It now has crit/stam/int making the belt BiS for overall stats. Minor run speed no longer stacks with other sources of minor run speed, so cloak enchant is now the way to go for minor run speed. Defiler's cloth boots aren't BiS anymore, except in situations where you don't use a minor run speed cloak enchant or something like Boar's/Cat's Speed.

You're right on the belt/boots. Forgot about that change - made the update.
Minor Speed does still stack with the cloak. Boar's Speed and Tuskarr's do not. I just retested this now to make sure. Tool tip shows 120% speed and my toons walking faster than a 110% toon.

It's a terrible Glyph for anything except dunking on bads in BGs.

It's the most viable glyph hands down in arena. Certainly questionable in a serious BG.

Nope. The changes to BoA trinkets give them stam instead of resil. Now it's best to roll with AGM/MoT or MoT/BoA pvp Trinket if you're not a human. Goblin Mortar damage isn't significant enough to turn the tide of any fight, and the 3 second stun is irrelevant considering the DR with other stuns. Extra health is so much better than anything else you can get from a trinket. Not sure why any twinks would dispute that.

I recommended MoT+BoA PVP. That post you quoted was pre 6.1. I'd still favor mortar over AGM as human though assuming you couldn't switch between them in BGs. A 3 second AOE stun is way better than a shitty purgable shield and 250 HP if you're already stacking defensive stats elsewhere.