Should I mention collaborators in the job talk abstract?
I think it's good form to mention your collaborators in the abstract if you're talking about joint work.  It's not as completely mandatory as mentioning them in the talk itself, but it's still good form.  Mentioning their affiliations, on the other hand, seems pretty weird to me and is not usual at all.

You're not going to be able to hide what paper your job talk is about, somewhere that's thinking of hiring you is going to know your paper list!  It is a bit of a red flag to me that you're thinking you can mislead people hiring you about when your research happened and who it was done with.  

(It's perhaps worth noting that sometimes job talks, especially in the last few minutes, touch somewhat on how the work you're focusing on connects to the rest of your research program.  It's not necessary to restrict yourself to a single paper.)