Can a person have hypertension and atherosclerosis but have low cholesterol like i do.

Yes: As an autopsy pathologist, i see this often. Sometimes i think people get fixated on serum cholesterol and forget other risk factors, and quite a bit of this seems hereditary or simply mysterious.

Yes: The etiology of atherosclerosis is only partly understood. Genetic factors and other components like triglycerides role and fatty acids is not fully understood yet.