Server Location and Upgrade Questions

I have a few questions that I need some help in answering. Keep in mind our Network monitor box is phsyical and everything else in the enviornment is virtual. We are planning on keeping Network Monitor physical.

1. Does Symantec require the Network monitor server to be in the same physical location as the endpoints it manages?

2. Does Symantec require the Network monitor server to be in the same physical location as the Enforce server and the rest of the environment?

3. What type and volume of communications occur between the Network monitor and Enforce server?

4. Does Symantec support an in place upgrade of the app from current version v12 to v14?Or must v14 be built on new servers?

Thanks in advance!