All that is fair(except the point of Jeter being self-serving and selfish). He probably could have hugged it out with A-Rod and made an easier path for him. However, A-Rod carried a rep with him upon his arrival and, quite honestly, aligning with him could sully your rep(and this was BEFORE his steroid admission).
A-Rod is a grown man and should be able to handle himself. At one point, they were buds. Only they know why that ceased to be.
As for self-serving and selfish, no one gives themselves up at the plate like Jeter to move a runner. Sure some of that is selfish(LOOK AT JETER!!! HE'S SUCH A TEAM PLAYER!!!) but he could hit more homers, get more extra base hits and drive in more runs by pulling the ball. He doesn't do that. As for less walks, that could just be a by-product of not missing. His power is down. Could just be a different approach, put the bat on the ball rather than attempt to drive it, or it could be he's seeing more strikes with Ichiro(who puts the bat on the ball a lot also) and Cano coming up after him. Pitchers could actually prefer to pitch to Jeter now.