These are some brilliant feature suggestions and improvements @riccardobusetti, and best of all I love that you shared them as a Supernotes card! My favourite one is definitely the “study mode”. 
Just to note some of these are already open feature requests here on the Community, such as offline mode, card depth and templates. Since we tend to keep feature requests to one single feature at a time so we can more easily keep track of them, I’m moving this topic to “Thoughts & Feedback”. If there are any particular single feature requests that haven’t been mentioned here on the Community, please do open them as individual topics – your suggestions are really excellent!