The first question is why is Locke in a wheelchair? Presumably, the sideways world resulted from Juliette setting off Jughead ("It worked") in 1977. In the original time line, Locke isn't tossed out the window until 2000.
The second question is, if the butterfly effect of Jughead takes Locke out of the "leader of the Others" game, he would never have been visited by Matthew Abaddon who gave him the idea to go on the walkabout, so why did he go?
The third question is, if Sideways Locke is not the neurotic mess that original time line Locke was, why would a man in a wheelchair go on a walkabout?