I would like for a trans activist to answer the question: "When you say that you wish to live as a woman, what exactly is it about the way you wish to live, that can't be included in the life of a man?"
Or is it actually a matter of wanting to be perceived as a woman, as opposed to wanting to "live as" one?
The only meaning that "living as a woman" would have in a feminist society would be in relation to female biology, I think. I suppose I am "living as a woman" when I'm throwing a dark jacket down on my seat in the board room before a long meeting, in case my tampon springs a leak. I felt like I was living as a woman when I was pregnant and feeling the movement inside and elated / fearful at the thought of the birth. I was living as a woman when I breastfed my baby, and then when the milk stopped flowing and I struggled with the feelings of disappointment around that. I am living as a woman when I get my smear reminder and my mammogram reminder and the low-level anxiety buzzes around the back of my mind until both are done and clear.
But in the absence of female biology (not a cosmetic approximation of female anatomy), what meaning can "living as a woman" have, that isn't antithetical to feminism?
There's the social side, of course, of being perceived as a woman. Wolf whistles or insults / comments on physical appearance. The threat of sexual violence. The assumptions about what your interests will be, the assumed limits on your aptitudes and intelligence, the continuous subtle and overt messages that you are mainly ornamental in purpose, and that if you're getting that role wrong or not working at it or too old to fulfill it satisfactorily, you are basically a waste of oxygen and best ignored or ridiculed.
I think that "living as a woman" or "living as a man" is meaningless outslde of biology. Being perceived as a woman or as a man certainly means something, but the differences in assumptions, cultural expectations and life chances based on perceived gender are exactly what feminism exists to combat.