Yes, that is the same Shark Boy. There was even a run of WCW Saturday Night episodes where Shark Boy wrestled, and he had his own group of fans in the audience wearing Shark Boy masks ("The Shark Tank").
Not sure what you mean by "making their own Warrior with the Disciple." Disciple turned face after Warrior came to WCW and started the short lived "oWn".
I think Warrior was over in his very first WCW appearance, and that was about it. He was just a complete bomb in WCW. On one hand, I can see why WCW thought the guy would work, since he was still a "name", and Hogan probably pushed to bring him in. On the other, their main event scene was so incredibly loaded already...I mean, for faces alone they had Sting, Savage, Bret Hart, DDP, Goldberg, Roddy Piper (a couple of those may have been nWo at the time, I can't keep track), there really wasn't room for Ultimate Warrior and his shenanigans.