Doffy had no help after Green bit. Less stamina doesn't make you less strong. Law fought Doffy to the best of his capabilities and failed. On the Flower Hill, Trebol only attacked when Law was incapacitated by Doffy. Law tried all his tricks on Doffy on the panel and failed.
No, they are not. Those are headcannon he pushed I try to discredit any rational and logical explanation to ZKK happening.
He took away Kaido ability to fly as a dragon. What evidence is there in the manga can no longer create clouds to fly? Are you going to tell me he needed both his horns to fly even though there's nothing to support that. He's assuming that the explosion didn't throw Kaido out of those magma caverns. Oda drew a scene that showed the caverns connects the part of the island where the explosion occurred.
There's no logic or thought behind it. It just somebody posting in rage because the thought of ZKK happening infuriates them.