>provide individual Services by providing membership benefits and electric tickets.
The key in your example is providing versus selling.
If you were selling individual services, some might be 1 and others would be 2, but your users are only purchasing a membership, which includes both digital and real services/items so my opinion is your app should only sell the membership outside of the app/app store. If you however break services out seperate from membership, and it doesn't sound like that is your plane, then you will use both IAP and outside payment processing.
You have both 1 and 2. When a payment results in the user, now a 'member', being able to do certain things in your app then you are 'unlocking code' in the app and you must use IAP for charges that result in this capability. When the user then uses that capability or 'membership' to make a purchase of something that will be used outside the app, like a ticket to an event or other real items, then you may not use IAP and may use a third party payment system. (When a user pays to be able to view some content within the app then you could allow that purchase outside the app and operate as a 'Reader App' or you could charge using IAP within the app - your choice.)
Divide up the charges into two catagories - membership and real items. Use IAP for membership. Use a third party payment system for real items.