A lot of things about your theory make sense, and I appreciate you sharing it, even if it should have just gone into the chapter discussion thread. My only issue is with the One Piece being the straw hat in freezer. I don't think we would be shown the actual One Piece so unceremoniously that long before the end of the series. It would be like, hey, remember that frozen hat I showed you years ago? That was actually the One Piece. I just don't see it going down that way. At this point I'm equally if not more interested in what the treasure of Hachinosu was. Whatever that was seems to be important to the overall plot.