Sorry, pisses me off anytime people say Taru PLDs run around getting one shot by everything.
Advicewise: Just gear yourself like any other tank. The only things I probably use that others probably don't are the 3 I listed, RSE2 Belt, BQR and Cassie Earring. I used to use Gigant until I got Valor Cape. I still use Gigant for my Cure 3 Macros. I do have 8/8 HP merits and I would highly advise them for any Taru Tanks.
Otherwise, I use all the same gear as others and swap in things like Hades+1 earring, Warwolf Belt, Swift Belt, etc. Regen3 takes care of the minor HP swaps from spells and such through the course of the fight. On top of the fact that I am usually manipulating my HP totals to self Cure 3 myself anyways.
Obviously I tanked plenty of things before getting things like full Homam, Ares's/Avalon Bodies, etc. So you can tank just fine without the perfect tanking gear as well.
1400+HP is pretty much all you need for most things. You can get away with 1300s as well, anything lower will probably be bad though. Getting owned in the face has nothing to do with HP though, it has to do with managing Utsusemi.
I also have Ninja and have tanked plenty of things NIN/DRK.(Omega,Tiamat,etc) NIN has a bit less HP, so it really pushes your skills to not make glaring mistakes but it's not some impossible task or something where you will be getting killed by mobs every 15m.
- FFXIAH.com - Link to some of my normal tanking gear if you care. I usually have Cassie where the Hades+1 is, I swap Ethereal/Hades+1 during the fight and leave Cassie fulltime. Obviously a ton of swaps, I blink a ton, Shield sets, Haste sets, full Enmity sets, Fire and Magic Kits, Vit set for Rampart, etc, etc.