User accounts

[wolfbgn]

Is it possible to have two kinds of users?
1.Without any priviliges, like it is now - read only (option for little kids who dont know what are they doing, there are such adults too).
2.Users who do not have the option to add, edit or remove devices but all other options for customization are available (changing maps, measurment units, username, password etc.)
Is it possible when registration is closed the button registration to disappear?