Lock user group from sending emails or changing lists


I've written Joomla components before and am fairly well versed with the MVC architecture but not quite sure how I would write an extension for mailwizz that extends/modifies the core app.

Basically we only want certain customers to be able to view their statistics but when an administrator impersonates the customer, all the options are available allowing us to send and edit lists etc...

Anyone have a clue if this is possible through the Mail Wizz extensions system?

Many thanks!