1, 3, 4 - fixed, thank you!
2 - still shows a white screen instead of a message after I click "edit".
But in this case I have no way to compare with a normal internet connection, maybe the problem is entirely on my side.
I think I'll write back again once I get to a wired line.
I think the issue is still that the editor didn't load with a poor internet connection.
Added an additional notification if the system can detect a loading problem.