PhoenixFearless

For your final question it will go Blackbeard, then Imu. Defeating Blackbeard will help him become king of the pirates, and then defeating Imu which will bring down the Red Line which will be Luffys final goal, or his "Dream".

I mean his "dream" because in One Piece Luffy has had two goals as stated in Episode 1088 there is a hidden goal he will need to achieve by the end of the manga besides becoming King of The Pirates.