I will setup powermta management console in your server

While this is technically possible, it is not a recommended setup. The sharing of resources on the machine may create an environment under load that could cause PowerMTA Management Console, PowerMTA, or both to become unresponsive.

Currently this is not supported. We may look to add this feature in the future, but for now if direct access to data is needed the accounting files may be used, as they have the same data.

PowerMTA 4.0 and later are the only versions of PowerMTA that support using PowerMTA Management Console. In addition, accounting file from previous versions of PowerMTA cannot be imported into PowerMTA Management Console. Manual import is not supported.

Currently the limit is based more on the limits of a given server than any artificial limitations in the software. That being said, the database should scale on sufficient hardware to over 100 million records.

While this is technically possible, it is not a recommended setup unless the virtual server has adequate hardware and the virtual server software is configured correctly. The sharing of resources on a mis-configured virtual machine may create an environment under load that could cause PowerMTA

This really depends on the amount of data each node is feeding PowerMTA and the hardware available to PowerMTA Management Console, but assuming each node is doing 1 million messages an hour, 10 nodes can registered at one time.