The texture you are referring to is probably a texture compound, skim coated and stamped or trowled to shape. It has probably been painted over a number of times. It is not removable. The material is bonded to the ceilings and unlike popcorn testure, will not scrape off. It could be sanded, but you are talking mega-work and dust. It would be easier to replace the ceiling or skim-coat to cover the texture. Asbestos is a remote possibility, but if you decide to sand the surface, test at an analytical lab that does mineral identification, and specify polarized light microscopy (PLM) test.
Wall paint is not generally infused with lead, but you can easily check with a swab test. These are available at your paint store and are an inexpensive color-change test swab. Even if lead is present, stripping wall paper should not pose a hazard provided you do not create dust, and wash you hands well before eating.