The hurry is the least of the problems with the writing. Off the top of my head:
* Why go back to such a last-minute point? Why not go back to when, for example, Soran was on the Enterprise and you had transporters, security guards, and forcefields?
* Assuming you want to bypass the easy sensible route as described above, why is Kirk picked? I know, if you can go to when ever, why not pick up somebody that's really an ass-kicker, or how about taking weapons or a ship with you?
* And why only one person? How about ganging up on Soran?
* How do you even know you left the Nexus for certain?
* How did you leave the Nexus? If you can't fly a ship into it and the only way found to possibly get in is to let it sweap you away on a planet's surface (which, by the way, how in the world do you find out that is possible?), how in hte world do you exit it so easily?
* If you can pick the solar system, galaxy, planet, and spot on the planet you can get back to along with a general time frame, why can't you put yourself someplace useful, like at the controls of the rocket?
* Man, of all the potential people inside the Nexus, what dumb luck you happen to not only run into another human, but a Starfleet officer and a previous Enterprise Captain! Lucky break is lucky break!
* If in the Nexus time has no meaning, then how does the Nexus know what time you are thinking of to go back to?
* How do you communicate with the Nexus? Is it sentient? Sentient enough to keep you alive, communicate with you, send you back in time, but not enough to avoid ships and planets.
* If again avoiding the easy sensible route from the first example, doesn't Kirk know anybody esle there that he can tell something along the lines of, "Hey, could you wait five or ten minutes, then come after me incase I get shot in the back like a little bitch?"
* How does it know which reality to send you to? If you have to tell it, how do you know which reality you were from? We've seen one episodes where the boundaries of time and space break own and multiple Enterprises appeared, so we know there are tons of alternate realities, so if the Nexus is a convergence of time and space, they're all mixed up and jumbled in there. So, how do we even know Kirk is dead? Is that the Kirk from the timeline of the show or a Kirk from an alternate reality? Then Kirk could still be alive in the Nexus. There could be hundred of Kirks in there, overwhelming tiem and space with the magnitude of awsome they have.