I was trying to make some connection between gold d. roger and luffy. I think that roger (being the extreme powerful guy that it was) decided to be executed by the marines. This, because of the secret of the ponegphlys that im sure is something about the weapons that can destroy the world (like the one that crocodille was searching) I believe that gold d. roger found some prophecy about one pirate of the D. of destiny that was going to save the world of that weapons. He made a pact with Garp to train his grandson to become that person or maybe it was already knew that luffy was going to be that guy. Maybe that is why shanks (he was part of the roger crew) decided to stay with luffy for a while so he could see how he was doing and also to be sure of setting some kind of encouragement for luffy to go sailing. Garp maybe believe that he was going to save the world (luffy) by becoming a marine. Whitebeard maybe was also aware of this prophecy so he sent one of his proteges (luffy`s brother to train with him). I believe that many of the characters that appeared in the journey know at some level of the importance of luffy. Kuma save luffy at the last moment, mihawk also didnt attack luffy and inform shanks about it. (why mihawk, one of the strongest shichibukais was worried about a crew that didnt have even a reward in their heads). Please answer maybe a forgot more details that make connectiones to this theory. Bye
Roger and Luffy connections
i think roger had a time time ability and could travell throw history. ithink he was born in the missing century and was the beginer of the d. family.