As an additional comment - my RIM node does not have a Proxy service installed on it, it is simply the repository service and engine service. I believe if I set up "Load Balancing" under my Central Proxy and Central Virtual Proxy, then the Central Proxy Service running on my Central Node will handle authentication and then automatically load balance following that authentication among the RIM Nodes and Central Node.
I am not seeing resources being utilized on anything other than the Central Node, however. I was led to believe it was a random load balancing, so I should be seeing utilization on the RIM Nodes. Is this true?
This choice is your's. There are pros/cons to each choice and the right answer depends on your architecture.
At a high level, if you specify multiple Engines for load balancing for a given virtual proxy then you will share the load between those two Engine nodes.
Many customers prefer the architecture of having the Central isolated from most, if not all, activities. So for these customers they would have an architecture like this:
Central: Central Virtual Proxy load balancing off the Central
Proxy Node: Proxy Node's virtual proxy load balancing off the Engine node