So I am new to pathfinder so take this with a grain of salt... But I haven't found any rule that lets you split up the +2 ability boost into two +1's. It really made me feel like I was wasting a boost just to get from a 17 score to an 18 score.
Maybe other people disagree with me..... or maybe I misread the book somewhere....but I think you should allow some easy way to get those odd number skills to even number ones, for us min/maxers out there lol