i usually don't post to questions i feel underqualified for, but you're only seeking opinions, right

?
depends on the waiver wire (i.e. Hill's worth on the WW Vs. what you could bird in hand get for Utley).
your reasoning seems sound. i have Barney too in one of my leagues, and boy howdy, that kid looks like the real deal. He bats second most every night and only had a little early may slump to speak of. Plays hard and seems to have fun doing it. I'm not so familiar with Hill, though (Phillips is my everyday 2B)
You might make some tentative trade offers for Utley, just to see where he stands in your league value wise, and that's going to increase, methinks, as he gets back into form.
Again, your reasoning sounds solid...long haul thinking over the quick fix type of thing, so i'ld just watch that one particular area and see where it takes you.