Home assistant has spent the last couple of years focused on improving usability to new users. A lot of it will self organise. What doesn't can mostly be set up easily via nice gui fronts, and easy to follow menus.

It's got an insane amount of functionality, which can be scary. However, you don't have to touch a lot of that. You only need to play with the bits you want, and it will hold your hand for most of it.

Couldn't do without it. I hope that it becomes so accessible that everyone can run it in the future, but it's not hard to dip your toes in now. If you don't have any dedicated HW you can run 24/7, you can get a cheap RPi. If you're ok splurging a hundred, try something like a zimaboard.
The latter has the advantage of coming with an app store, which is docker wrapped in a click-to-play coat. I have a couple zimas but I use compose, so haven't tried it, but it should be very friendly.

Yes