Do you mean if Starmie would be overpowered for OU? Hard to say, probably depending on what you consider overpowered. Starmie would be on par with Dragonite and Zam imo. The metagame would likely get a lot faster with all the move additions so it's difficult to determine brokenness. IMO, if you are saying that Zam and Dnite would have to be banned from OU, then Starmie would probably be a similar story; however, I don't think any of the three Pokemon would completely need to be moved to Ubers the same way Mewtwo and Mew needed in real RBY. It's probably a matter of how you define brokenness, and, of course, of how accurate our speculations are because it's impossible to visualize a brand new metagame without testing it.
P.S: On another note, what makes a difference for Alakazam is Calm Mind. Psycho Cut would just be a slightly better fourth move at best (over Seismic Toss / Reflect) on the real RBY Alakazam we all know, and would not be used if you give zam the possibility to run Calm Mind anyway.