I'm not sure with the Momo theory being the bloodline of a Shogun. I have two reasons for that.
1. See, on the third page of chapter 701 in the middle panel, Momo says that he will become the Shogun of Wanokuni as a boast to Luffy, when he says his line about becoming the Pirate King. What sense it would make for Momo to brag about becoming the Shogun, if the title is hereditary?
2. If Wano follows it's Japaness theme, Shogun are choosen, not born. They were appointed by the Emperor of Japan.
Now, Momo being cousin, or even being groomed to be the heir to the throne of Wano I can see. That would not be unheard of.
Meteors aren't just floating in Geostationary orbit waiting to be pulled down to earth. They would likely have a very high velocity relative to the earth and it would therefore likely take quite a lot of force to pull one into the earths gravitational well.
And even disregarding that, we see that Fujitoras gravity has enough power to protect him from the meteors he summons. I think he really did went easy on Zoro because of that bar thingy. He seems like an honorable person like that.