I can't speak about your question on trying to conform to the gender I've transitioned to, because I haven't yet begun any transition process.
The gender role thing is something that caused me to begin questioning my gender in the first place. As an AMAB, I've more recently realized that the male behavioral and appearance expectations are just too restrictive for me. I've spent my whole life trying to fit in, not always quite successfully. I even remember my dad asking me, on more than one occasion, if I was gay. I always knew I liked girls, so my response was always that I was certain I was not gay. And since I didn't know that there was this whole other gender spectrum in addition to the sexuality thing, I left it at that, and slowly learned that I ought to act more "male" or face others' disapprobations.
As far as appearances go, I've found out, thanks to slumber party events at my dorm, that I rather enjoy having painted fingernails. I haven't yet had the privacy to try much more than this, as far as clothing and makeup are concerned, but I've enjoyed the yoga pants I purchased online.
Unfortunately for me, I'm quite self-conscious about what others think of me, and as such I have not the necessary boldness and nerve to wear anything other than stereotypically male garb (and occasionally some stuff that is a bit more androgynous, such as skinnier jeans).
However, my interests are quite heavy on the stereotypically male side of things: physics, computer science, video games, sports.
I'm guessing the cis people who break stereotypical gender roles are often classified by passersby as gay/lesbian, but I'm not sure about that. I would also guess that one reason that cis people expect trans people to pass is because they're not yet comfortable seeing what appears to be a man dressed like a woman or a woman dressed like a man.
I hope that answers a bit of what you asked; I feel like I rambled and bounced around a bit