You didn't like the best action sequence in the movie? Like, seriously, no argument, the opening was awesomesauce. How anyone can say they like Star Trek and not like the big naval battles/captain going down with his ship thing is beyond comprehension. When it's not moralizing, this is what Star Trek is
about. The adolescent scene was silly, but combined with the early scenes of Spock it worked as a framing device for the rest of the movie. Showing Kirk and Spock at odds even before they ever meet was interesting, and it was over pretty quickly, so in terms of scripting, it got done what it needed to and didn't overstay the welcome.
Kirk's promotion comes as a bit of a surprise until you realize he has a fledgling Admiral and the entirety of Earth's population rooting for him. Warheroes get
prrrrrrrromotions!
The black hole thing bothered me a bit, moreso the fact that they stuck around to shoot at something caught in a gravity well than the fact that they created the gravity well in the first place. But, it's Star Trek logic. It could be that once the red matter was expended, the rift was closed, or it could be that Kirk was simply gambling that it would be enough to do the job where the Enterprise clearly was not.
As the introduction to a conceivable new cast, this movie set out to establish who the people were. Bringing in a nemesis would be jumping the gun, and while it might be nice to imagine everybody getting together and coming up with a master plan it wouldn't have been likely in the context of the story, having all these fresh-faced cadets able to work as one machine. Instead, they hinted at what made each of these people special and why their ultimate voyages might be so successful.
Not sure what unexplained knowledge you mean, Araes, but it's obvious they went out of their way to appease people who would wonder why the movie was so different from the Star Trek they knew, and alternate timeline pretty much covers it. Omagnus went over this already, but carbon copy characters would do a disservice to the movie because it would only appeal to one type of person. It's a movie in broad strokes because it wants to appeal to a wider audience. Once they move on to a second or a third, they'll start giving the characters more specific obstacles to overcome. As IGN pointed out, for this first movie, the lynchpin is Kirk vs. Spock. Really, as it should be.
Also, Nutty, you are giving Trekkies a bad name, and that is some feat.