4. Main Character's Shielding
Khan takes out most of Starfleet's high command and San Francisco, beats the Enterprise to all-hell, and yet all the main bridge crew survive, plus 1 in fact with Carol Marcus. Christopher Pike being the only causality we truly feel for in the entirety of all the horrific events that transpire. It was even foreshadowed that Chekov would be offed, getting 'redshirted' early in the film. We'll buy the resurrection of Kirk, just give us a semi-important character death to balance it out.
3. But What About The Klingons?
As mentioned previously, a federation task force entered Klingon space killed dozens of warriors, destroyed a few ships and all on their home-world. Tensions between the two races were already high according to the Admiral... so what about this incident wouldn't incite war? At the end, a year onward there is no mention of any large Klingon retaliation for this clear act of war. What has happened to our favorite Vikings in Space? Are they just more mellow and understanding in this timeline?