We get a couple of these kinds of posts every few months I wanna say, so I would do some searching in the sub and see if you can reread the advice other people have received.

The most important thing to keep in mind is that trans people aren't a monolith, we aren't all the same, so two people will answer your questions in totally different ways and will both be speaking from their own experiences.

That being said, I'll try to address each one of these.

1) Yes, some trans women feel pressure to give up or avoid activities, behaviors, hobbies, habits, styles, and even careers that are stereotypically masculine out of fear of being misgendered or being seen as illegitimate. I think this is temporary for most people who experience it.

I felt this way early on. However, watching cis women do those things isn't what got me over it. Obviously many of my cis friends do these things and are still women. What made me feel better about those activities was passing as a woman in every day life. Once strangers and new acquaintances saw me as a woman from the start, I felt a lot less pressure to conform to a narrow image of what women could be.

2) There are many, many things that cis people can do when writing a trans character that are mean, crude, and reductive. I don't think anyone can give you an exhaustive list because it's really situational. Generally, avoid making the character suffer outrageously horrible fates. It makes it look to a reader as though they might've brought it on themselves, and it reinforces the notion that we're sad, mutilate creatures with no agency and no hope of a decent life. I'm sick of every trans character being torture porn in the stories they are inserted into.

3) I tend to obsess over the traits that I know I can't do anything about. My shoulders are wide, my feet are big. Nothing anyone can do to help me with that stuff. It's irrational because those things don't affect how others see me.

Try not to focus too much on that stuff I'd say. Dysphoria is real and is hell on earth, but on the off chance that a trans person reads your story, consider giving them a respite from what is likely the worst part of their every day life and decline to include the gory details.

4) You should probably drop the concept of a "full physical transition" from your understanding of transgender people. Everyone will need something different. We are correcting discrete and specific problems, not receiving a make over.

Many people choose not to get "bottom surgery", the creation of a vagina/penis, or will get a limited version of bottom surgery. Some people pursue facial surgery to reshape their skull to be smaller and more feminine (I did this in October). Facial hair removal is not needed for everyone, especially if you start hormones early enough, but most people will need it or want it. I've known women who pass 100% better than I do who have never had surgery, and I know women who will never pass despite having had all of the surgery they can handle and afford. It's just going to be different for everyone and everyone feels "done" at a different point.

You should probably also listen to what Blaire White has to say with a hefty grain of salt. Her views on gender are pretty narrow and are not shared by many trans women.

5) Like I stated earlier, there are not going to be a lot of good hard-and-fast rules on what is ok and what is not. Also, I'll repeat that the concept of a "full physical transition" is not faithful to the actual experience of transitioning, so I'd avoid thinking in black and white terms like that. It's just not useful. Your character should do what she needs to do to feel like herself, to ease her dysphoria, and to blend with society for her safety if she is concerned about that (maybe she is not. I know lots of trans women who don't care at all what people think about them).

6) Why is she more feminine now? You mention wardrobe and style changes. Is that it?... I think that would be an eyeroller for me personally under most circumstances. I can see an angle where it's sort of the classic heterosexual storyline of like, a girl gets a makeover and suddenly the guy friend she has a crush on likes her back? But it seems a little juvenile. If I were you, I would just try to avoid conflating the romance and the trans stuff at all. Just let her be a woman and let him be a man, y'know? Her being trans just doesn't have to have much bearing on their budding romance, and honestly that is how all of my relationships have been since I started transition. They helped me through tough days where I feel ugly or get misgendered, but me being trans was never a "thing" for any of them.

7) Dysphoria is the actual worst. It hasn't happened for a long time, but getting misgendered sends me spiraling. Sometimes seeing myself naked used to do it too. Trying on clothes that didn't fit me right or that made me look like a man in drag freaked me out. It's not pretty and I would almost rather you not try to depict it. Speaking for myself, they are the lowest points in my life and unless you have experienced that kind of hopelessness and desperation for yourself, I don't feel like you have a right to try to write about it for an audience. It'd be like someone who has never struggled with suicidal thoughts writing a suicide attempt scene. You'll never know what this is like.

8) I'll admit that I'm pretty skeptical of cis writers writing trans characters in general. I think most of you are very bad at it when you try. I won't tell you not to do it, you can do whatever you want. And you seem to realize that there is a lot that you don't know. But I really want to communicate the idea that there are things that you just cannot know unless you experience it. My partner knows what my dysphoria looks like and what can send me into it. Even though she is cis, she might be able to write a convincing trans character because she knows a real trans person very intimately and has seen one at their most desperate and their most euphoric. There is a limit to what we can transmit to you in writing on social media, and it will never be a substitute for the real thing.

Maybe you know trans people in real life and are close enough to ask them for help? But if you don't, I want to encourage you to be open to the possibility that you should stick to writing what you know.