hypercrites

First, what sort of signal does his appointment send to Iran?

I don't know if it sends any signal to Iran.  Obama is the master signal sender and he seems to want to stay out of Iran's face so the Hagel pick seems fitting.  Elections have consequences and this is one of them.  Personally, I don't think poking a rabid dog with a stick constantly is beneficial.  Let Iran bark away but if Iran bites or attempts to bite then hit them with swift and deadly force.

And, second, what sort of signal does appointing an apparent anti-semite send to American Jews?

Is Hagel an anti-Semite or is he perhaps just a cranky old guy?  I've read a couple of the articles purporting to show his hatred (maybe mistrust) of Israel and the Jewish people and I can see where he might just be  the kind of guy who doesn't cater to special interest groups of any kind.  Maybe he doesn't have very good people skills or is more direct than your average guy.

I don't know much about Hagel but I don't like to label people "haters" of selected groups unless there is rock solid evidence.  If there is I haven't seen it.

BTW. If he doesn't have good people skills that's a pretty good reason for him not to be running the DOD because the last time I checked, there are a lot of people there.