From the get go, I have been against signing Mookie to a long term deal like you mentioned. If the Sox don't think that they can extend him before he hits free agency, then it makes all the sense in the world to trade him. I felt that way last year too, when we were all feeling really good about the team and didn't foresee this collapse. It just makes too much sense not to.
I know this won't go over too well, but frankly, I'm tired of Mookie's attitude about getting the most money in free agency. I know that baseball is a business, and he deserves it, and bla, bla, bla, but give me a Xander Bogaerts attitude any day of the week over a Mookie attitude.