to the forwarding server can sometimes be a bit dicey. I tried to forward inventory at different times during the day. You could cut down the dataclasses being forwarded, to only those required for your reporting needs.
Package servers can't be shared amonst different NS, and NS6 doesn't have anything close (unless you count package replication solution) to NS7's replication and heirarchy.
That being said, I'm a proponet of having lots of package servers.