Ask user for authorisation to assist

No, it's not supported.

You could send a text message to the user,
or we could even tell epoptes to wait for the user reply to the message,
but it doesn't make much sense to add such an option now since we're allowing running arbitrary commands to the users.

In the future we're planning to implement different access levels to the clients (sysadmin, teacher etc) so it might make sense to add that option then.

Italian privacy law requires that a user gives his consent, before another person can access his PC.

Then you probably need to wait until different access levels are implemented in epoptes before using it. And I imagine you also shouldn't be using SSH and other similar services. There's no point in having the user consent for viewing her screen, if you can run arbitrary commands and do whatever you want (including capturing her keystrokes or screen contents or accessing her files) without her authorization.

So, just preparing for future access levels, could I ask a couple of questions about it?
 * Is this also valid for public labs, like school computer classes? I mean, isn't there always a sysadmin there that can access anything?
 * Which of the actions that epoptes supports, could e.g. a teacher perform to pupils screens in Italy without asking for their permission? Is e.g. screen locking or sound muting also prohibited without permission? What about getting client information or fullscreen teacher screen broadcasting?