I still maintain that the Klingon foreheads is by no means a continuity issue, but rather a simple evolution of technical abilities. Originally to make different aliens they just dressed them differently and gave them different ears. Some got masks, but they looked awful. By the time the Motion Picture came along, the money and technology was there. Why not take advantage of it?
You could easily say the Andorians are also a continuity issue, since they looked ridiculous on TOS and pretty damn good on Enterprise (even though I didn't like the show, Andorians looked good).
Axia, it is clearly explained as alternate and not altered. Spock couldn't go back because of the whole convoluted red matter thing. The time travel was an accident, he wouldn't be able to choose when and were he wound up. And ultimately, Volcans are an endangered species, so the "logical" thing to do would be to go back in time and prevent Volcan from being destroyed, and even stop Nero from going back in time in the first place, as well as prevent Romulous from being destroyed stay in the alternate future and help rebuild and preserve the culture.
I am not a big fan of this new Trek either, but I do find your reasoning on the matter interesting, Axia. This new Star Trek is a take it or leave it sort of thing. Sure, the half-assed "rebooted" story line completely changes forty years of ST history. But all that ST history is availble not only in beautiful, digitally remastered anamorphic DVD of the highest quality, made with true loveand care, but it is all also making its way to us in HD glory. Even if the contrived new films were to be bold enough to come out and say, "Forty years of Trek now means nothing! Mawhawhawhaw!" your DVD collection can boldly tell it to go screw itself while it continues to be an awesome collection.
The Star Wars prequels on the other hand do literally try to erase 30 years of Star Wars history, and are beyond a doubt revisionist bull shit. They very visibly and tangibly change parts of that history. Not only that, but these revisionist films also attempt to completely remove the original films form existence (because if any of us are dumb enough to still want them, we can kindly go watch them on obsolete equipment in an obsolete format). The only half way decent version of Star Wars on DVD, and likely the only version that will ever be on BD, is this revised version that effectively kicks aside 20 + years of Star Wars history. And even those three altered films in all their anamorphic restored glory are perfect examples of rushed and poorly done DVDs, while the prequels are quite honestly, to their credit, some of the finest, best value, two disc collections I have ever seen.
Imagine all the original ST stuff only existing on outdated formats, and the J.J. Trek being given a fantastic DVD/BD release. It would piss you off wouldn't it? Search your feelings, you know it to be true.