Great post!
The only thing I would change is removing Lester and possibly Iglesias from that list. You mentioned hanging onto Lester if he can turn it around and I'm certain he will. It may not be this season but he will not be this bad for his whole career. He's fairly affordable going forward and is what he is when right- a solid #2.
As for Iglesias, I like that he seems to be improving his offensive approach to the game as he's gotten more at bats under his belt. He reminds a lot of a young Elvis Andrus- with more glove but less bat. His defense is off the charts and has an impact on the game that is rare. Like you mentioned, the organization does have a bit of a niche in acquiring undervalued offense. If you're dead set on getting the pitching back to a respectable level, you have to place a premium on defense- especially up the middle.
Unless you're getting better value, they need to stick with Iglesias since they've already invested a lot in him.