Bolster acts as a stats buffer and gives you a better chance but as other people already said in this thread, you will never be as strong as a fully geared R15 (all class specificities apart of course), which is the top Rank for T1, just thanks to Bolster.
Also, If I was you, I wouldn't rely too much on doing lots of damage as a Tank, you wanna do DPS, make a DPS but face the squishyness that comes with it Tanks' DPS is sustained, and tbh, unless you have R40, the right RR and gear, to me it's pointless to even try to go "DPS" Tank because you'd be waaay more useful as an actual SnB Tank until R40 because that's what you're supposed to do. (except maybe SM where the Spirit dmg attacks give you a considerable boost)
The issue you might also have with IB, is that you have to build up your Grudges to be at 100% of your potential.
If you're getting that frustrated with your IB, just make a White Lion for example and you'll see the difference when you get crits with Sundering Chops in people's backs
Spoiler:
That is indeed what Bolster does, nothing to do with gear. Basically the only thing that ties gear & Bolster together is the fact that every level your base stats grow, so Bolster boost diminishes, hence you'd better get some gear or you'll fall behind people of your level.Sulorie wrote:Bolster is indeed a multiplier to mainstats and armor/resists.