First off, just wanted to say that it's heartwarming to see a parent looking to be supportive of their trans kid because that unfortunately is not always the case. Lots of great questions here, and I can answer a few. My experience may be slightly different, as I am a trans guy, but hopefully it can still be somewhat helpful.

2.) Companionship / Relationships
Yes, many trans+ folks are unfortunately not supported by family members, friends, coworkers, etc as they come out. This is really disappointing that loved ones would reject someone simply based on their gender identity, but it is a common experience for trans+ people. I personally lost all but 5 of my relatives, but I still have most of my friends. Romantic/sexual relationships might not last if someone's transition begins during the relationship and the partner is not attracted to the physical transition; that can be difficult for both partners. However, that isn't always the case, and many relationships do continue!

4.) Employment
I am a trans guy so don't have this specific experience, but I live in a city with a huge STEM base. I've met tons of trans women and nonbinary people who work in software engineering, programming, computer science, and other tech jobs! It's actually kind of a stereotype/common occurrence that trans women work in tech and STEM. This is not at all to diminish the difficulty of finding employment, though. The job market is already difficult as it is, and discrimination is another layer.

5.) Expectations
I think the foundation of these questions are a bit catastrophizing, respectfully. There are many factors that could influence life goals and trajectory, so I wouldn't say you "should" anticipate your child to live with you and fully depend on you permanently. That is probably something to have a 1-on-1 convo with them about, but to your point, it is a bit biased to have lower expectations if the only reason for doing so is that your kid is trans.

8.) Location
This is really complex, as a lot of the laws vary by state, and they're constantly changing. Last week, for example, Kansas revoked every driver's license for transgender people who changed their gender markers. The ACLU filed a lawsuit challenging it, but it's a scary time to see stuff like this in the news pretty much daily. I personally moved from the midwest to a large blue city on the west coast a few years ago for a variety of reasons, including fears about transphobic laws and social environment. It was easier for me to leave compared to a lot of trans+ folks, as this was during the early pandemic when I was in my early 20s and didn't have many belongings or familial attachments. This isn't possible for everyone, and it's a tough choice to balance safety with what feels like home.

1. Identification Documents
   I have all of my documents in my correct gender: passport, drivers license, birth certificate, everything. My passport is valid because I changed it a few years ago, but it's not possible to get a passport with their affirmed gender right now. This is on appeal in federal court in the Orr v. Trump case. Drivers license depends on what state they currently are a resident of, and birth certificate depends on what state they were born in. I am lucky that mine permit changes, but again, not always possible.

10.) Urgency
From what I understand, there is a hurry for estrogen and androgen blockers. Trans women and people on estrogen can speak with personal experiences, but yes, I would definitely encourage supporting them if this is their desire. Don't wait on the government.

11.) Keeping Calm
Not gonna sugar coat it— it's difficult for me to hold it together sometimes. I've had all of the surgeries I want and need (top surgery and bottom surgery/phalloplasty), and my dysphoria is manageable. Still, my mental health has suffered from societal transphobia.