jkitsune: Fair points.
Re: Morales, it could just be my Richie Sexon-meter going off, but I do believe that power-guys that get their numbers through swinging a lot (and striking out a lot) tend to fall off quicker as they lose bat speed into their mid- and then late-30s. You are right that there are some examples of DH/1B types that hit well into their mid- or even late-30s (hey, Edgar was a solid producer through his age 40 season, going .294/.406/.489). However, I think those tend to be exceptions.
Furthermore, the power hitters that do make it are usually good at taking walks to make up for their loss of power - like Edgar. This is not one of Morales' strong suits, unfortunately (he's got a 25/66 BB/K ratio this year, so not good). If he can take more walks as he gets older, I would roll the dice on him through his age 34 year, but he hasn't shown an inclination to stop swinging so much. I mean, I think it's worth a risk because he won't cost that much, more than likely, but I don't think that I am underestimating power hitters that swing at everything THAT much. Maybe somewhat, but I feel like Morales does not have the skillset to compensate for his eventual loss of bat speed that is occurring even now.
Re: Iwakuma, I think you are right on this one. We are running Saunders and Harang out there now because we don't have many options in the first place. Even if two of Ramirez/Hultzen/Paxton/Walker are ready to go next year, it makes no sense to get rid of a low-cost SP that is a reliable #3 at worst. Iwakuma isn't the guy that he was over the first half of the season minus his last two starts, but he's definitely a good player. Keep him unless our socks get knocked off in a trade offer.
I felt this way about Fister a couple years ago, and I think Iwakuma deserves that sort of approach as well.