1. Jack used a Vivre card to get to Zou but he had no idea where Raizo was but was 100% certain he was there. Only people who could have known about the Zou plan was the jumpers Kinemon, Kanjuro, Raizo and Okiku.
not necessary , Shinobu and Raizo were in the same Ninja group to be honest i think she was the one who rejected him , they might have a vivre card of him from the past.
or they met the traitor as they came from the past and trusted him/her
another possibility they knew while chasing them that their destination was Zou , the same way BMPs knew the destination of the strawhats was Zou, and some like the yonkos have resources , it is not impossibile to get their hands on a vivre card . BM has pekoms as a subordinate , there is a mink in the revos , a mink in Law's crew , a mink in Hawkins crew, so it will not be impossible that Kaido has a mink in his crew as well.