So far (I am dub anime only for mha), Frieza. Far more charasmatic and although his motives are a bit cliché (rule the universe) they are at least understandable and he has a goal to work toward.
AFO, on the other hand, from what I can remember said he wanted to be a devil. A straight up scourge on the world. Be evil for the sake of being evil. Kind of a weak motivation. Also, he has supposedly been collecting various superpowers for over a century and the ultimate attack his brain can come up with is a really strong punch. Frieza was much more entertaining, both in dialogue/mannerisms and fight choreography.
He was not providing context, he was lashing out. I am talking about the beginning of Endgame. He was talking like creating Ultron was a decision that was above and beyond reproach. Ultron nearly made the human race go extinct. Tony's self-righteousness and ego would not let him realize that Steve was right. He was messing with stuff he did not understand and kept it a secret from the team. Let us also not forget that Tony had a hand in helping Thanos by bringing the time stone to him.
Tony is the type of guy to berate Steve for opposing his creation of Ultron. The fact that Tony creating Ultron anyway nearly ended all human life on Earth? Not important. I am Iron Man, I am always right, do as I say.
He is not worthy. He sacrificed at the end of Avengers 1 as well, he still could not lift the hammer in AoU.
As to whether or not Zod can use X-Ray vision: There is no outright showing of him using it however, he did blitz Kal-El from the other side of a skyscraper, right after Kal had lost sight of him, and he most certainly can use x-ray vision and super hearing. He also jumped into the right floor of the right building after their initial clash. Not easy to do considering he went through another building so Zod would not have line of sight.
To be fair, the Thanos that said "I'll do it myself." Was not there at the final battle. This was pre-AOU Thanos who was about to send Ronan to get the power stone. Still, even after he said that he sent Maw, Cull, Proxima, and Corvus to get the Mind and Time stones. None of them succeeded. It is a huge flaw that is inherent to his character. He reminds me of Naraku from Inuyasha. Way too reliant on henchman for crucial tasks.
He wouldn't have to. If he's really goal driven here like he was in MoS, he'd just use his X-Ray vision to locate it, kill Clint and put it on.
If you wanna push it back to when everybody comes back, he'd still be able to. He's faster than everyone else is and none of them would be strong enough to keep him from clenching his fist or snapping.
In short, he's definitely snapping his fingers.
You read my mind. Thanos is a lowkey idiot. Could have gotten the gauntlet himself and completed his goal but he stays true to form and lets Nebula do it instead. He gets killed by a human as a result.
Contrast with Zod, who overthrew the science council in person, went to get the codex in person and secured the genesis chamber himself. He would just send the black order to fight the Trio while he grabs the gauntlet himself. Clint would not stand a chance.