They're not, you are just horrendously over-stating what they (the stats) are telling us. I'll just give you bullet-point formula from the top-down, just to keep it easier on you:
1) No, you have to use 3-years woth of UZR data when computing UZR. It's not enough to just look at three individual UZR numbers and take their average because it is based on a sliding average for each and every season, meaning the numbers fluctuate violently. So, just simply averaging a bunch of UZR numbers won't accomplish much because they were all based on their own average. Now, I know for a fact you didn't go through and re-compute UZR with this goal in mind, so how about you just drop it.
2) Nobody was saying Soriano has a crappy arm, his is actually pretty good, but one's arm is just one small sub-set of fielding, particularly so for a position in the OF. Just because the numbers indicate he has a great arm from the OF doesn't make him a great fielder overall.
3) Funny here how you force yourself to defend Soriano's obvious sub-optimum grade in an overall fielding category. Look, like I said with UZR: it doesn't matter, at least for our purposes, what the average is for that stat, it really doesn't, because it is all based off of one year of data or a few years of wildly-fluctuating averages. All we need to know is what the stat puts right in front of our faces: Soriano is pretty shitty at saving runs from his OF spot. End of story.
4) The rest of this is just the same kind of crap: you list a stat, and even though the stat shows Soriano to be pretty bad, you somehow twist the perspective in such a manner so as to make Soriano look to be the victim of the calculations, usually by listing where he sits in relation to the rest of the MLB. I'm only going to say this once more: that shit doesn't matter. Where Soriano is relative to everyone else is an irrelevant discussion, because what we are talking about here does not include everyone else, and what's more Soriano's position relative to those people is more than likely the result of some random fluctuation of the aforementioned volatile averages.
So, nice try, but no dice. Soriano blows, end of story.