I would very much want to be able to simply change or delete the original email adress that I made when creating the account.

The first email adress you create gets a version with all the available suffixes at the end.(example@protonmail.com, example@pm.me etc)

Thoes original adresses can't be changed, deleted or disabled and it annoys me; I want to get rid of them! Would be very cumbersome to create a new account just for this.