Public Admin was removed. How does this affect the settings/rights of the other user levels?
Does "User" level gets more rights? Does Admin get also more rights? Basically, what is the difference between each user in the before and after?
Superadmins stay the same
Users stay the same
Administrators stay the same as before.
So it doesn't affect the settings of the other users in any way. The former public admins you hade, if I remember well, would have now been set as "users".
You have to give them admin rights just like you did in the past. The only difference is that they will get that information from the admin area and not from the front end area.