Does it matter in what order you schedule an endometrial biopsy, a pap smear and an ultrasound for postmenoposal bleeding - or timing between them?

Probably not. Though your doctor would most likely do the pap smear and endometrial biopsy at the same time, and in the office. The ultrasound may be before or after, and may be done at your doctors office, or at a hospital or imaging center.
Not in your case. Since you don't have a normal period , the timing doesn't matter. I would schedule all those in one visit if your doctor's schedule permits it. If you need a detailed pelvic ultrasound, then it is done by a radiologist.