Povetkin will be very dangerous early. He wobbled and hurt AJ early until AJ started to figure him out. Even though Povetkin is now 40, he's only ever lost to Wlad and AJ and he's a much better boxer than Whyte.
Povetkin has 6 rounds to get Whyte out of there, or as you say I think Whyte gets him late.
Pretty much how I see it. If he were five years younger, Povetkin would be favourite for me. However, we saw him get hurt by Price and KO'd by Joshua. Even Michael Hunter, a relatively small HW, had him buzzed in the last fight from what I recall. I think Povetkin knows he is unlikely to go the full 12 and will probably try to make things hot for Whyte early. Whyte also looks in good nick and is tough enough to survive the early onslaught. Hopefully, it will be a good a fight as I think it could be.
As for Taylor, I expect her to adopt different tactics and use her boxing skills. If she elects to go in and out quickly and use her footwork, I think she could make it a comfortable night and win a UD with no dispute.