If there is a change in management can my new employer make me sign a job description without my having read it?

Employers can generally do anything they want regarding application and hiring policy as long as they do not discriminate against you. E.g. If they permit other potential employees to take the paperwork home to read before signing up. However there must be disparate treatment based upon prohibitive conduct by the employer. E.g. "prohibited factor" means a factor prohibited by law from being used in making employment decisions. Under Executive Order ll246, as amended, the prohibited factors are race, color, religion, sex, and national origin. Under Section 503 of the Rehabilitation Act of 1973.

They won't terminate your employment over that, but there is no downside risk in signing. Job descriptions don't mean much they tend to evolve over time and anyway an employer can change your job duties unless you have an employment contract that says otherwise.

Yes, they can, but would you really want to work for an employer who does so? You may be waiving various contract defenses, or at the very least, making it much harder for yourself down the road by reading something without signing it. I would never let a client sign something unless I or the client had read through the document first.