I have issues getting sms pass through to a secondary profile, especially if it is a group message or contains media. I have to remember to open the messaging app for it to actually refresh and download/notify me of new messages.
It didn't used to be like this but started maybe a year ago.
No root is a major security feature, you have chosen an OS that prioritizes security.
Use some other browser if dark mode is really important to you.
I think the launcher is good and I can't think of anything to improve on it. I'm happy it's the default, but I'm sure you can switch to a different launcher if you want.
Pattern unlock is also not there because of security.
You can try it, but don't cry if it bricks.
The newish one I bought got GrapheneOS instead. That worked without a hitch, but it's got more than a few problems.