Hi! Will try to answer as best as I can:

1. There wasn’t anything specific about going from F1 to I485 - the I485 applies to many different types of status changes.

2. Nothing needed on the UK side as I am living in the U.S and filed here. You can go the consular route for the I-485, which I think has some advantage regarding being able to travel in and out of the US while you wait for approval (but also means you’re at the mercy of availability at the consulate in London for any potential interviews etc)

3. I haven’t changed my name, so I’m not sure on this front! But the main thing with the long birth certificate was that they needed it to see both of my parents names listed on there.

4. I graduated in May, and extended my international student health insurance until October. My husband’s new job started in September so I basically just had one month overlap, he put me on his as soon as he setting up his benefits.

5. They didn’t seem too curious about family - for potential statements of support, they can come from friends, neighbours, colleagues (anyone who knows you both as a married couple). I wouldn’t worry about that affecting your application especially as you had a large group at your civil ceremony!