On SharePoint members can also change settings like "open office files in desktop app". How can I prevent members from making changes in the SharePoint settings and give only owners these rights?
Site members always can edit list settings like you mentioned "open office files in desktop app". This is by design and we have no way to prevent site members from doing this.
You can only inform and instruct all your members not to change the settings. Tell them this is not a user-level but a document-library level setting. SharePoint is a portal for team collaboration, and the role of people cannot be ignored.
There is an alternative of course, but I'm not sure if this will work in your scenario. That is, go to the document library and stop the document library's inheritance of site permissions, and modify the permission level of site member group from Edit to Contribute. In this way, site members will not have access to the list/library settings page, but they can still add, delete, and edit items/documents in the list/library.