1. Probably a good 35% of the dreams I am female in them. I am usually conscious in someway of how this is different from the normal. Sometime I am cis, sometime MTF, sometimes I really don't know but I am know I am female. Often times, they are quite profound, of course in retrospect they are always profound. I remember one where I looked in the mirror at myself topless. But more than just visual stimuli, I could feel how delicate, softer, lighter I was. I had this profound chord wash through me of contentedness. Gone was that testosterone-driven anxiety; I was whole.
2. Yes, I have dreams like this, and can leave me very content. Often times though, I am somehow attempting the act and either find I have something I don't want to be there... Or, I have a female partner and I want it back and can't have it back!! Very confusing. But yes, dreams of men and women as me as a female are quite common.