Are this thinks possible?
If you write a new ispconfig apache plugin and rerite some of the forms, then yes.
We have not chose this type of setup as it will cause you a lot of trouble. For example if the user mueller changes his username or if the website gets a temporary domain during development and then the domain gets changed when the site goes life, you will destroy the installs of most vms systems in your kind of setup as the base path changes. So ispconfig uses a much smarter solution based on generiv folder names with symlinks for the domain names for easy shell navigation.