Service Charge and other taxable fees

In our existing POS, we can design and use items like a "Service Charge", which is taxable and very much like your 'hard-coded' Delivery Charge. We're currently able to create, modify, or delete these items as required. As such, we have no "Delivery Charge," but we do have a "Service Charge," that applies to special orders and/or groups of 6 or more. This 'fee' can be applied either as a 'set' or 'fixed' amount, or as a '%' of the entire ticket. Another example would be, supposed I wanted to implement a "Carry-Out fee?" Or a "baggage fee?" Or any other type of "service" which is taxable. Currently, more than 30% of our orders have some type of 'fee' associated with it, while we have ZERO delivery fees.

The Delivery Charge should be able to be toggled on or off, not hard-coded.

We should be able to add other service fees, or fees in general, much like we do menu items and taxes.