I think Valdez is a much better hitter than he has shown, so far, this year, and better than all of these guys on the list, but his defense is so bad, he'd have to be a good enough hitter to win the DH job. This is doubtful.
I have no issues DFA'ing Dalbec, but I'd like to see who the back-up 1Bman is. (Ref makes sense.)
Romy might be the best of the bunch, which isn't saying much.
I do not think DHam plays good enough defense, even at 2B to be worth keeping.
Reyes looked okay, last year: this year, not so much.
They all look like they could be DFA'd, but replacement infielders are not likely any better.