They have the money to make a strong move ... plus the market provides a strong financial incentive ... the wins pay off in a way they don't in say Tampa Bay.
The Porcello extension is fine. It's not wholesale - and clearly he did not pitch well for 3/4 of the season - but that is the going rate for a pitcher of his relative merit (on the high side granted), who is young enough to project some modest improvement. The path to him being worth the contract is not difficult - and they are not locked into any physical decline.
The Panda contract was the diciest of the three because I just don't think he's that good. I know why you give him a big deal - they had literally nobody at 3B, he is 29 so there was some projection if you squinted hard enough, and Fenway was tailor made for his Wade Boggs-esque spray chart. But those were opinions I did not share.
Ramirez I thought made sense as a 3B, and less so as a LF (although his impossibly bad fielding at LF was not something a reasonable person could have anticipated given the long history of potted plants, cinder blocks and guys named Kevin Mitchell who have patrolled it adequately). But he was brought in to hit, and that he did not hit was surprising. If that part gets fixed, the fielding sins are tolerable - I am going to assume a return to the infield will help him rise up to "non Vine-worthy". The Red Sox will undoubtedly try to move him - and the market for Ramirez might not be as barren as it looks (especially if the Red Sox are just trying to deal him, return be damned) because the contract is not that long and his non-hitting reads "injury-driven fluke" for now.