Add a button for the client where he can click on "Find next available date" and then the booking engine goes through and finds first available slot

This would be called flexible pricing and will be in consideration but not in priority as we do not get a lot of requests about this one.

Add possibility to set Maximum and Minimum allowed time before service booking per each service differently

To have within the admin app a button "WhatsApp" and there he would be directed to his personal WhatsApp where user could call or message the client

Add a possibility to apply discounts, like coupons and gift cards to packages.

Possibility to allow to view and manage bookings without the ability to change schedules. Consider the request not allow to see a long list of clients - can that be done and still for that person to be able to see the calendar? Maybe we could add calendar viewer role and they could only manage and adjust that but not go into other functions.

When customer purchase a package, membership or gift card there should be an email notification to company email. It should be possible to edit template and disable it if needed.

We already have this - see here https://help.simplybook.me/index.php/First_and_Last_Names