If this is Bill (merchgod) who you're talking to I'm sad to see that he's jumping to conclusions on this one. Unless I missed some background information, the 2 logs you posted isn't enough to justify spending $200+ on a new MAF sensor.
The positive fuel trims could be due to many factors, but a bad MAF sensor is one of the last I would look at personally.
I have seen more ripped open turbo inlets that have caused this problems than any other thing.
I would start by doing a boost leak test off of the turbo inlet. Look for leaks coming from before the turbo. This would cause your problems.