True Strike is 100% apply chance... so far. I haven't seen anything stop that.
Advantage almost doubles crit chance, from 1/20 = 5% to 39/400 = 9.75%. The base chance is still 5%, but Advantage gives you two tries at it for each attack.
And yes, using that sequence on an 8 HP goblin is just asking to make part of the sequence useless. Only use it on high-HP enemies.
