No he can't but he can run in the air or use soru The laughing scene wasn't canon or maybe not since oda can't draw a lot in a week so he sometimes tells the animators to add in something he wants Or perhaps he laughed quickly before falling down or just good dramas
Luffy can make things rubber in gear 5th. This means he can grab things like clouds or lighting to hold on to. Also gear 4th bounce man can actually fly.
