it looked like Gol D. Roger, simply walked up, and turned himself in, as if he was content with everything. His Nakama like Rayleigh wasn't apparent, and I don't understand that whole deal. Therefore is it a precursor that Whomever actually gains the One Piece, end up loosing all of theyre nakama, or a large majority?
I don't think that was the point of what Roger did. Two things that we need to remember are the questions that Robin and Usopp asked Rayleigh when he was telling them about Roger's final days.
Robin asked Rayleigh if he knew what the Will of D was, and he answered yes. But, he also told her not to hurry, walk the path with the SHs, find the info and come to her own conclusions. He also mentioned that, as she was at that time she wouldn't be able to change anything, the Roger pirates and the Ohara scholars were the same boat.
Usopp asked if Roger intended to set off the great pirate era, and Rayleigh told him that he didn't know, and that answer died with Roger. That leads me to believe that Roger saw the true face of the world and could not change it. Since he was about to die of illness he set things in motion for that change to occur, this is further supported by WB's final words.
I think that was Roger's aim.