First, yes we absolutely can, as diamond mods, protect posts. So can any user with 3500 rep or higher.
Second, I find a lot of sites have two major problems with protecting their posts. First, it's used way too much. I would only protect a post that 1) has an external source of a lot of attention, like being featured in a blog post or tweeted by a twitter with a lot of followers and 2) is actively being abused by new users.
I would agree that the posts on that could use some cleanup, and you could argue that I could be more aggressive in removing some of the lower quality posts instead of waiting for people to come back and clean them up themselves. (You'll note for some of the lower quality ones I've left comments asking them to make changes.) But I wouldn't say this is a prime candidate for being protected - if a post gets a bad answer once a month, it doesn't need to be protected.
I base my thought process around Shog's post on the matter. If you feel a question should be protected, flag it and we'll take a look. If you feel an answer should be deleted but has somehow slipped through the review process, flag and and we'll take a look. Those are the best ways to clean things up.
