I guess we are just assessing potential here in different ways.
My POV has always been that OF are easier to come by than 1B just since there are so darn many of them. You are much more likely to find a good replacement value OF on the waiver wire than a 1B, so for that reason Howard's elite slugging potential takes slight precedence over Beltran's all-around OF package... That said, they are both sure-fire first-round picks, so I consider it a fairly even exchange at the end of the day.
In our league setup, we have 10 hitting categories and 10 pitching. However, two of the pitching categories are only available for relievers (Saves, Holds) and so starting pitchers can only contribute to 8. Rios does it all (power, average, SB) and so he is a potential 10-category stud. To me, that evens him out with Hamels (who by all means is an awesome pitcher on the rise).
I basically agree with your assessment of Hill and Vazquez... but that's the tail-end of the deal anyway, and I don't consider it that important (if he counter-offered someone else similar, I'd probably do it).
Thanks for the thoughtful feedback. I eat this stuff up, as is painfully obvious by now.