Is it possible to have "repository running as an application" use 1. database on another machine 2. place content (files etc.) on another machine (e.g. the alf_data folder)
The logic behind it is that my data storage server has a lot of hard drive space plus would allow automatic backups - hence make use of it while keeping Alfresco application independent.
The share interface is a user interface for alfresco new in Alfresco 3.
Yes you can run the database on another machine, in fact this is the "normal" way of running a database.
You can have the content stores on another machine by using some sort of remote file system protocol or network storage product.
Some caveats, Alfresco makes heavy demands on the database and file system so it is important to have good network connectivity between alfresco and the servers.