Guild Wars 2

So was wondering if anyone hardcore pro can awnser me…..

I am running a thief currently and playing shortbow – blast finisher support with other stuff, but repseccing to tank like unicorn build. Many say its amazing, but i keep hearing after lv 30 factals it cant do a thing compared to real “tanks” ….

So my question…what are real tanks and what build?
Engi? With bunker? A guardian? Warrior?

If we are the topic….i hear there are quite op healers out there…like shouter warrs…is that true?
Warr was supposed to be my alt (if i roll any at all) but the 70% of servers most palyed class is warr, and i dont like to play what the most ppl play to.
So if i roll one anyway, i would love to know if it is worth to roll one (for pve mostly) Can it fill many roles? Or it will be a boring crap dd er?

My warrior heals for nearly 4k per 20-30 (?) seconds with shouts. And I think that’s not even optimized because healing isn’t my focus. I couldn’t say anything about the rest, I heard water ele’s and engineers can heal really good too.

@ Rolling a warrior for PvE, I love it. burst damage with crits can be ridiculously high, it’s good at tanking tho not nearly as good as my guilds guardian is, as said before: the shout heals can save your group many times when running dungeons etc. etc.

So its viable for Fractal tanking after 30?