5) Would Crystal Fragments combined with Blood Magic be good? It seems like Dark Deal, Hardened Ward, Harness Magicka and Liquid Lightning could all proc it for free damage and healing.

EDIT: Sorry for the multiple posts. I didn't see the edit button earlier. They kinda have it hidden..

1. All classes tank the same way. Use taunting skills (pierce armor from the 1 hand-shield skill line or inner fire from the undaunted skill line) to grab aggro on the large adds. Use pull skills to chain the smaller adds (chains on a DK, frozen device on a warden, swarm mother monster set for the rest). Use a cc root skill like talons to lock down the smaller adds in the AoE. For larger encounters, it's grabby the boss and facing them away from the group. Stamina recovery is disabled when blocking, so the differences between the classes is how they recoup stamina while blocking. DKs and wardens have the best toolset to do this which is why they're considered "the" tank classes. Other tank builds you read about online are gimmick builds that are not used in end-game content.

2. Frost staff tanking is a gimmick. It doesn't provide the tools to tank end game content. Stat distribution depends on your race, but most trials tanks dump either all their points into health or do something like a 54 health/10 stamina split

3. I'm going to focus on the two viable end game trials tanks. What makes DKs strong at tanking are chains, talons, the helping hands passive, and battle roar. These tools give make DKs the best tanks for the hardest content in the game. Wardens have good tools too. The betty and the green balance passive provide good stamina return. They grant major buffs to their team when using icy fortress. The real distinction that warndens bring, however, are trees. Secluded grove is a huge source of healing. In this way, wardens are more PUG-proof than DKs--trees make up for a bad (or dead) healer. Pick a DK if you're planning on running in a regular trials group. Warden if you plan to PUG

4. For trials, always double sword and board. Even with a huge amount of health there are attacks you need to block, and sword and board give you the passives you need.

5. Those are magsorc DPS skills. Sorc tanks are a gimmick. Dark deal takes a second and a half cast time. Dropping block for that long in a vet trial will kill you.

Now, all of this advice is for vet trials and vet DLC hard mode dungeons, the hardest group content in the game. If you aren't interested in tanking this end game content, do whatever you want. I've "tanked" vet dungeons with dual wield and bow in medium armor with inner fire on my bar. 95% of the content in the game doesn't require a best-in-slot try hard tank. If you just want to mess around with friends, do whatever class you want and whatever setup you want. Just throw a 1HS or inner fire on your bar and have fun.