I hope Scotty doesn't always act this goofy throughout the film. He's supposed to be an experienced command officer as well as an engineer. I hope they don't abandon that.
I don't think we have much to worry about. It's been noted in several articles that Pegg worked with Doohan's son on-set to "perfect" Scotty. Also, we have have a very
small handfull of lines to go off of, and there has only been one or two goofy ones, IMO.