Hi there!
I have some questions about MTF transitions, among a few other things, and this site seemed like a really welcoming place to ask them

Before we get started - I would like to apologize in advance for anything I say that may come across as rude or offensive, I really don't mean it that way! I am just very new to this so please let me know if any of my terminology is coming across the wrong way.
First there's a bit of back story...
My partner was born male and.. well this is where it gets tricky. My partner, who we'll call Cassie from this point on, likes to wear womens clothing when we're at home. Before we got together Cassie was not in a very accepting environment - the few people that did know about Cassies clothing preferences were just terrible to her, it got to the point where Cassie didn't dress up for years.. until we met.
I think that everyone looks their best when they're being themselves, and it doesn't hurt that Cassie looks freakin' adorable all dressed up, so she's been starting to open up about the whole thing again. I've asked Cassie a few times if she'd ever want to dress up when we aren't just at home, and she seems pretty uncertain. I'm having a hard time figuring out how much of it is because of how she was treated in the past.
She's mentioned hormone therapy before, but only in passing and when she does it's to say that if she was going to do a MTF transition she should have done it when she was younger.
Cassie is in her midtwenties and is quite tall, with broad shoulders and very masculine features. She has a lot of body hair, and a lot of facial hair.
I'm worried that Cassie secretly does want to transition, but is just unwilling because she doesn't think she could pass as a woman anymore.
That being said, maybe Cassie really is just content with dressing up, and doesn't want to do a full transition? This seems unlikely to me, but in either case, I want to be more sensitive to what Cassie needs from me as a partner.
For example - I don't know if I should call Cassie a boy or a girl. I don't know if 'he' or 'she' is more appropriate. I have stopped saying 'my boyfriend' and replaced that with the gender inclusive 'my partner', but I want to do more than that.
I tell Cassie she's beautiful and buy her feminine gifts (like panties and breastforms) but she is still always looking for reassurance that I'm okay with this. For example, she'll regularly say "are you sure this doesn't freak you out?" or "if you ever think it's too weird you can tell me and I'll stop" and it just breaks my heart. I feel like Cassie is holding back on taking steps towards a transition because she thinks that deep down I'm not okay with it - which couldn't be further from the truth. Everyone deserves to feel comfortable and happy in their own skin, especially my beautiful Cassie, who is the kindest, sweetest person I've ever known.
So.. sorry for the huge back story. I guess my main questions are.. what are some gender neutral terms I can use when referring to Cassie? Is there anything that can be done to decrease masculine features such as broad shoulders, body hair, and big hands? And what would be some really accepting, comfortable places to go to kind of.. test the waters? I think it would help if Cassie had an option to go somewhere dressed up, knowing it would be a safe environment. I was thinking of asking Cassie to go with me to one of the dragshows the local gay bar puts on, but I don't know how that would come across. Is asking a MTF person to a dragshow the same as asking a hollywood makeup artist to a junior high cosmetology class? I just really don't know, please help!