I have an existing live Exchange 2010 environment setup with iApp template f5.microsoft_exchange_2010_2013_cas.v1.2.0 and our College is migrating our users/Exchange to another domain. We have another full set of Exchange 2010 servers to handle the new environment. I would like to create and test the new environment before we go live. Can I just create the new Application Service with the new template f5.microsoft_exchange_2010_2013_cas.v1.6.2 I downloaded? What do I have to look out for so I don't break my current working environment.
Yes. An iApp is a template used to create a service. You can create multiple services using the same template.
Just create the template with a new service name and different virtual addresses.