Multiple Web Sites/Roles on Azure, Impact of staging server

Multiple Web Sites/Roles on Azure, Impact of staging server

I'm looking to set up two web roles or websites on my Azure Cloud Service.
The websites need to share the same database schema. I use NHibernate ORM,
so I have to make sure that both projects are always using the same data
model, or else it will cause major problems.
I've researched setting up multiple websites on a single web role (which
seems odd to me, can't I just run multiple web roles, each with a single
site)?
http://msdn.microsoft.com/en-us/library/windowsazure/gg433110.aspx
Like any good developer, I use a staging server. If I have to manually set
the domain name is configuration files, how will azure know not to be
sending people who visit that domain to the staging server?! I.E. If they
visit blah.foo.com and I have two deployments (staging and production), is
IIS going to be able to know only to send people to the production
environment?
Please advise on the best way to go about doing this.