Curiously i also wanted to make this thread before. It seems we think the same way. xd I also think that Kisame is a bad match up for Minato. With his dome of water, Minato could not use his kunais properly, and Kisame is even faster than Minato in the water. Also Minato will have to face the problem that he couldn't breath.
But even inside the water, Minato still has his chance, but for that he will have to accept being hurt. He will wait that Kisame hurts him in taijutsu to take an advantage of it to put his seals on him. Kisame is faster so Minato couldn't deal with his speed, but if Minato stays and wait the time Kisame attacks, he can actually do that. And when he pose his markings on him it's over.
But i know Kisame is not idiot. He knows Minato capacities. So he won't risk to attack in taijutsu to let Minato do that. He will attack from distance with his shark jutsu that absorbs chakra or even his other mountain of sharks he did against Gai and against that, Minato will have no chance from what we've seen.
But that happens only if Minato is caught in kisame water dome which is not forced to be so. Minato can summon Gamabunta and get out of the water quickly, and outside the water, Minato has all his chance to win this fight. Minato is even more than clever. I count on him to search for the best solution to make him win.
So i still see Minato winning, but it will be a hard fight.
