It would be cool, I agree, but i don’t think it will happen. I wrote about this a couple weeks ago, here. I said that the biggest problem is the fact that Fujitora is there on the island. The fact that in the latest chapter Fujitora was directly ordered to take in Luffy and Law only makes it all the less likely that Luffy will claim the island as his own. Fujitora has already seriously pissed off his superiors, and it would be so freaking ridiculous if he just stood there and let Luffy personally claim Dressrosa as being under his protection. Even if Luffy did that, it probably wouldn’t mean a darn thing. Like you said, Luffy doesn’t have that kind of influence yet. His name is still nothing next to that of the Yonko, even if he did just defeat Doflamingo. And plus, what would Akainu do if Luffy claimed Dressrosa? Just stand there shaking his fist? Nah, it’s more easy to imagine that in a fit of rage Akainu would sail to Dressrosa and plant a WG flag on Dressrosa and shout on a worldwide broadcast that Dressrosa is the Marine’s to protect and if Luffy has a problem with that he can come try to fight for it. So, because of how fruitless and probably detrimental it would be for Dressrosa itself for Luffy to try to claim it as his own territory, I can’t imagine he will even try to. Besides, Luffy doesn’t even WANT power over anything. The only reason he put a claim on Fishman Island was to stop Big Mom from destroying it. But the Marines are already on Dressrosa, and the one trying to destroy it (Dofalmingo) has been defeated. At the moment, there’s just no reason for Luffy to think that he needs to keep protecting it from anyone, or that the Marines couldn’t handle it if there was.