Kaido was going to intercept Whitebeard, never was it said he was sneaking up on him during Marineford. I'll address the Shanks thing below with Zoro's quote.Then why would he have to sneak up on WB during MF? Shanks stopped Kaido as well, yeah ik that doesn't mean much but it's still something to consider.
Nope. You have no no idea how that confrontation went down, it's not really usable in a debate like this because we have zero details on how it happened.
Shanks stopping Kaido from going after WB. According to portrayal Shanks > Kaido. Given Dragons hype, which is on par with that of likes of Shanks,WB and Roger. It's possible for him to be above Kaido.
There's no way any Yonko is gonna fight with another Yonko and it won't be an extreme diff fight. Seeing as Shanks arrived at Marineford without a scratch, we know a fight between them never happened. Not only that, but if Kaido fought Shanks, he wouldn't have much to gain even if he won. Him and Shanks, being Yonko, are already recognized to be on the same level as each other. The Yonko also don't usually fight against each other, so aside from ¨Oh a Yonko fought another Yonko, that's odd,¨ Kaido wouldn't have really gained anything from defeating Shanks. Instead, he'd lose his opportunity to intercept Whitebeard before he got to Marineford and be in a condition where he'd be unable to fight, much less combat the Marines and Whitebeard at one time, which would have had to happen as by the time the two finished, Whitebeard would have already been at Marineford. Therefore, it'd make more sense to just drop it and acquire what he was looking for another way.
Shanks could have also made a deal with Kaido. Before you say ¨But Kaido can't be reasoned with!¨, that's not true. Kaido can be reasoned and made deals with, as seen with the fact that he's involved in deals with Doflamingo and Caesar. He just can't be reasoned with once he's angry. Shanks could have simply managed to make him a deal that he liked, avoiding anger and being why he dropped going after Whitebeard. This is equally as likely as you simply saying ¨Oh Shanks stopped him cuz he's above him¨ which is what makes this situation unusable: Unreliability.