I actually mastered my grenades first, i was 25 notoriety when it was finished.
I'm working on all of my level 15 weapons quests right now. Its funny to watch some of the higher levels doing double takes when they see a lower level person holding a siege charge
But I am having fun doing my pirate this way. What I'm thinking about trying is doing the boss battle by myself, and if that doesn't work, well, won't be anything special, hahah.