Lexi,
I do like the way you approach the issue and agree with your last statement that it's not anyone's fault and not bad, it's just what is. Indeed, I am the same person regardless of how I'm presenting however it seems I often feel more at ease and open when I'm Sarah. It's nothing I do intentionally, but I've had too many perceptive people tell me I'm more calm and engaged at those times verses when I'm being the guy. I do try to modify my walk and talk somewhat, partly I believe to better convince myself and pursue that calm center than it is to try and fool others. I'm definitely not trying to pass, just not behave or appear in ways that add one more challenge to whoever is around. Although things are changing in society, and changing at a rapid pace, it's still difficult enough for most people to deal with the concept of Transgender, without adding too much more with a mixed presentation.
So I guess the real challenge is to find ways to open the gates and allow those positive traits to show up more when I'm not wearing skirts and makeup. Maybe I already am and don't realize it. I wonder if the person others see, be it Sarah or Dave, gives them cues of what to expect and they prompt me just a little subtly changing my behavior. Or does that put too much on others, adding to the list of things I can be aware of but can't control?