In my experience, HR departments for some companies do have this kind of material. However, the hiring processes for many places are inaccessible to people with certain kinds of disabilities, so they are not likely to even make it to interview stages of hiring.
In general, yes. There's a few exceptions, but in general you should have an accessible version for the visually impaired (or, really, any of the groups I list in the article. Are your training videos captioned for the Deaf? Can someone with motion issues navigate your HR site using Tab or adaptive devices? Is the language overly contrived or the font and color choices bad?)
Just "deaf" here. "deaf" people who aren't part of "Deaf cultre" are just as unable to hear as "Deaf people". In fact, the average "Deaf" person may be more likely to be able to hear, since "Deaf" is cultural (can be opted-into) and "deaf" is biological.
Yes, which is why HR departments will generally make digital copies of these materials available, i.e. for use with on-screen magnification or TTS.