As far as Kirk's advancement in Starfleet in the JJverse, I pose this: Kirk is a genius. Kirk is a natural leader. He's the 'Good Will Hunting' of Star Trek. End of story.
I guess in all the hubub of folks wanting to pick apart the first movie, they forget that Pike tells Kirk that his aptitude scores are off the charts and asks him if he likes, "being the only genius-level repeat offender in the Midwest?"