I would have interpreted "CAD drawing" ad DWG, yes. A PDF might be OF a CAD drawing, but it could also be a scan of a hand drawn sketch. If they wanted a PDF of a CAD drawing, they should have asked for it that way. I have seen that done, I like it when people are clear.
MUCH more often than that, I see a requirement for "CAD drawings" and if you send them PDFs, they reject them and insist on DWG or DXF format.
OK. Depends on what state of the project. Prior to award of contract I'd be disinclined to offer anything in a format that could be edited by
Side note on the "Dead Sea" jokes; If the Dead Sea were only sick, would it not be the "Sick Sea" or the "Not Feeling Particularly Well Sea"? Once it's called the "Dead Sea", it can't, by definition, be sick...