almost everyone is running 4 blade bravo's ... if you would like to have less prop slip you can get into a 5 or six blade works well, but beware that when you add blades your prop slip will go down. this also is tougher on the drives and can cause more failure...
not sure, i'm not very familiar with the trs and speed master splines, but if there isn't anything on the outside of the prop it's probably on the end of the prop either up against the drive or the washer and nut.