from the Cardinals end (allegedly). If they sign Oswalt, they may go with a 6 man rotation at the beginning of the year. Why? Because Carpenter is old and threw a ton last year including the postseason, Wainwright is coming back from Tommy John, Garcia and Lohse wore down as the year went along, and then Westbrook sucks. I can't stand him.
And as far as no trade clauses- remember that doesn't necessarily mean a player can't be traded. It just means that the player has more of a say in where they are traded. For eample, if Westbrook doesn't want to play for the Astros, he can use the clause. If he wants to play for them, he can "revoke" it.
What they may do is start the year out, figure out that Westbrook still sucks, tell him that he is moving to the bullpen and if he doesn't like it, they can trade him or release him.
And as you said, they are likely going to lose Lohse and Westbrook next year- they will probably replace once with Shelby Miller and they can replace the other with Oswalt- with a one year deal at a low rate- and then I think they will let Berkman walk too- and replace him with Matt Adams. If they have a brain, they will extend/re-sign Wainwright and then go after someone like Josh Hamilton next year with the 25-30 million that they are saving among others.