I guess it depends on a lot. At some point I started to pass and was living life as a woman. People started to have a hard time believing I could be trans or that I could be the same person as my deadname. At that point, having a male gender marker on my ID was a liability and a problem - it was going to create issues, people would maybe think it was a stolen ID, etc.

So I would say you should take seriously the need to update your name and documents - and update as many as you can.

Here's a resource that might be helpful:

https://transequality.org/resources/name-and-gender-marker-change-101

I lived in one of the most anti-trans states in the U.S. when I transitioned. I was still able to file a name change petition in the courts, went to a hearing and answered some simple questions (basically whether I was changing my name to avoid creditors or debt, whether I had a criminal record, etc.), then once I had the court order, I went through the process of updating my name and gender marker on my documents. I think I actually started with my passport, I simply renewed it and back then you could just select any gender marker.

Once I had the passport it was easier to update all the other documents, often the passport with my legal name and gender was accepted as proof.

Depends on your current and birth state. Some states still allow gender marker changes without evidence of surgery or clerical error. My birth state required surgery and I recently got that, so I'm working on changing mine. Problem will be Social Security which now doesn't allow changes under any circumstances and Passport which may or may not use the SSA inconsistency to deny changes or invalidate the passport altogether as fraudulent. We'll just have to wait and see how it's implemented now that it's no longer allowed without birth certificate changes. I'm not hopeful, but as long as my state continues to allow changes for the enhanced driver's license/real ID, at least I'll be able to travel domestically for now.

I got my new birth certificate in September this year so it is still possible, although I'm in a blue state (Minnesota). You should still be able to get a court order to change your name at least, and maybe sex but that really depends on your state. Even though you can't update federal documents now, you should still be able to use those court orders later.

Also if you have mismatching info you can use the court orders to show what's correct. I did that when I got my passport last year since I only had my name change order at the time so I didn't bother to get a new birth certificate then.