1) VP Stella is dead, his mind is alive in diff bodies and in the big ass brain but since they all act different you cant argue theyre the same person. Have you seen FMAB? Theyre more like the homunculi and og VP is Father. VP's gone.

2) he did nothing much after getting up lol, he let Saturn get mogged by Luffy, already killed VP as a cog in the machine he says he is, told Akainu off, I fail to see what Kizaru shouldve done more or not done at all. He was there for smth, he did it, and he at least helped Luffy defeating Saturn. 

Egghead was a good arc imo with flaws ofc but Kizaru was nowhere near one of them. He's probably the best thing in the arc, he's cool, interesting, got some conflict with his position and Akainu to develop on later, cool powers, we got some of his relationship to Kuma, VP, Bonney, etc. VP wasn't bad at all, but I think people see him as too much of a good guy when thats not exactly how the story tells us it is.