I am still mid-level and my GLD is my first time tanking any game. But I came in after researching the role.

As far as being horrified by low level gear, basic competent play makes up for a lot at mid-levels. I accidentally went into Haukke Manor still wearing my "around town" gearset instead of my "full battle regalia" set and tanked happily through the first mob before I remembered I was supposed to be wearing plate, not a velveteen shirt (hazard of multiple personas).

Had a few DF runs with Conjurers who just spam Stone instead of healing... made it through because I always cross-class Cure, and use Convalescence when it's off cooldown. And ask them to focus on keeping us alive, watch the little party health bars please... "Why is the GLD healing the CNJ?" "Because someone has to."