AC3 missing 1 assassin and stuck please help

I have just completed the story missions and have 5 assassins unlocked on my team.

1) I have no clue how to unlock the other 1 assassin there are liberation missions when I go to them in Boston there is nothing to do or anyone to talk to

2) All available assasin mission in the other east coast states all say 0% chance of success of completing for my assassins? Meaning I have no missions available with a decent success rate for my assassins. Is calling thgem for fighting support enough to level them up? What am I missing?

3) I can craft things like a hats how do I make Conor wear the hat?


please help