During Raids, by the way, there will always be 2 Priests and a Sorcerer healing me so isn't Endure better to give them time to heal me? If I use Tension Relax, it just heals me during time and it's not enough to resist while Endure reduces damages from EVERY monster that hits me. Isn't that right..?
TR is generally used to help cases where it's prohibitive for Priests to drop large heals, such as when a fresh wave of adds spawns, it's bonus aggro to yourself via self healing and allows priests to sit on the heals until you establish aggro.
It can also be an emergancy in cases where a healer dies and you need to turtle out a particularly damaging phase of an encounter.
In general though, unless you are somehow threat capping your groups you need to make a decision about how valuable tank-based utility vs tank-based DPS is to your party.
Skills like Rage Strike, Brandish, and Berserk add pretty much nothing to your tank utility beyond the first rank, while skills like TR, Parry and Endure can be used to mitigate damage in high damage situations.
Brandish and Rage Strike are both fairly mediocre to level, with Aura Armor, your Brandish at rank 1 already doubles the threat of a Sorc's LoV AoE and is 1.5x greater than a Ranger's Arrow Shower, not to mention that no one should really be AoEing a large pack as soon as they spawn anyways and once you've gotten one rotation in you shouldn't be losing aggro.
Magnum Break is also better than Brandish when tanking 3 mobs or fewer too.
A simple tank-oriented build that includes Battle Tactics looks something like this:
If you really want Berserk you can take 4/5 Aura Strike and 1/5 Parry, but imho Parry is much more useful to a tank than Berserk, unless somehow you're managing to threat cap your dps, an extra 20% dps for 30 seconds from the tank doesn't make or break encounters, but having 100% parry for 10 seconds every 60 is very very useful for mitigating overall damage.