The only thing I want more for Luffy is to become a weapon user now. Like, not being too reliant on his weapon like for example Zor and other swordsmen but using it when in need. That's why I was a little excited because of that fake leak. Though we're probably too late into the story for it to happen anyway.
How could a weapon be stronger than king kong gun lol, maybe if Luffy had awakening, but at that point he could buildings as weapons anyway.
Haki "Not touching" invalidates the need for one against people with passive damage like Akainu/ Maggelan.
Luffy is a brawler, like Garp, the strongest Marine of his era.