Regarding the introduction of the Narada into the TOS Trek universe leading to tech advances; consider Nero was around with his big super ship from the future for 25 years. While waiting for Spock Prime to show up, who knows what may have been discovered or studied, or even shared, and by or with who. Even if you remove the barely canonical Klingon prison sub-plot, we could infer that Nero sold off technology, shared it with alliances he ran across or other elements he contacted or ran up against along the way while biding his time, even the Romulan Empire itself. Poisoning the past didn't seem to be something he worried about, only surviving long enough to get his revenge. Even his hanger bay seemed to be full of other ships from other worlds... Kirk once worried about one communicator being left behind in a pre-warp civilization, consider a whole garage full of future alien tech wandering around space, not just the Narada herself.