Oen Server for everything to External Servers

Hi All

Question 1)
I am a new virtualmin pro user and have a copy of it installed on one of my test server for shared hosting configuration (FTP, Email, Web Hosting, Groupware etc);

I would like to ask is it actually possible and easy to do in separating the server functions out to different servers? Example Email as one server, Groupware as one server etc? and still have it managed by virtualmin?

Or is it much better just to keep everything into one server and when the amount of users grows, add another server?

Question 2)
Is it possible to implement high availability for a virtualmin server? Example from webmin interface?

Thank you!