You definitely have the right idea about trading big money players now for keepers for next year. I think this trade doesn't benefit you all that much. I don't like Wieters at $19 as a great keeper option. He has regressed this year and was a product of a lucky .348 BABIP last year. Cueto at $9 is the real target here, and Ramirez is a throw-in. I like Mauer at $24 about the same as Wieters at $19. I would make the trade if there was no other option, but you might be selling yourself a bit short on your players. People commenting here aren't understanding that you are 100% competing for the future, not this year at all. I would try to extract a better keeper option than Wieters. If possible, you could add in more big money players to entice the other owner to throw in another keeper like Cueto.
http://www.rotoballguru.com/the-nathan- ... -equation/That article should supplement your thoughts on the matter, though it seems you already have a great grasp on things.
Choo, Rasmus, Strasburg, and Boesch will all do great things for you next year for very little money.