Exchange server 2010 + Additional Domain Controller + Site & services modification?

Hi,

We have one primary domain controller (dc1.sdps.com), that is linked to the Exchange server and also we have fail-over domain controller (dc2.sdps.com).

My question is

1. if i creating an addition domain in different location (dc3.sdps.com) , can it will affect my exchange server or not? If it does what are changes need to be made?
2. Then if i modify the sites and services (adding multiple additional domain controllers in multiple locations and configure the subnet and sites for domain replication) can it will affect my exchange server or not? If it does what are changes need to be made?
3. if i add new domain in the same forest (dc1.sd.com) and create a trust relationship with primary domain controller (dc1.sdps.com).
   1.  What are the change need to be made, so that my new domain also access to the exchange server