Here's my two cents on it:

Yul did play Survivor, even though there were others on Aitu (Candice and Jonathan) who did as well. You're right in saying that Yul never saw that Candice wasn't on board -- at least he didn't totally see it, but Candice was also too closely aligned with her tribemates on Raro. She allowed her emotions to control her and that's why she mutinied. And by flipping at the time that she did, she plotted and schemed too much and backstabbed before she had to. Jonathan did a similar thing, although he was already seen as untrustworthy then.

You also don't give Yul enough credit for his making his Aitu 4 alliance work. He likes to lead by consensus, and therefore he took all of the suggestions of the Aitu 4 into consideration. He also made sure they were comfortable. You could say that he subtly manipulated things so that nobody else in the Aitu 4 wouldn't go against him. The key is subtletly. He tried to help himself out without making it look like he was helping himself out. He was the one who saw that Ozzy had formed the beginnings of an alliance with Nate and that's why Nate left when he did. And although the decision to get rid of Jonathan was a group decision -- ask Ozzy & Yul himself -- when Adam said that if Yul got rid of Jonathan before Parvati & Adam himself that Adam would give Yul a vote at the final Tribal Council, Yul went for it. That's more plotting & scheming than you think!

Sure, there was luck involved and the twists helped Yul in his path to the million dollars. But remember what Alex said in Estee's Survivor fanfic at herfinal Tribal Council: everyone plays the game at one specific point in time. They can only play the game as it happens in front of them. Look at Cirie -- she knew for the most part what was happening around her and was probably the smartest player in Micronesia but twists beyond her control helped knock her out.

That's the only point I'll add to your critique of Yul. Yeah, Yul had luck go his way at certain key points, but he was strategic enough to make the most of the good luck and mimimize the bad luck. That's what any winner must do.