PS: If anyone has a better idea for questions I should be asking, please let me know. I'm a newb!
To be honest, it's a test with no consequence for failure that (in VR) you can perform several times over three seconds. Given a few minutes, you really should be able to learn all of the main things you want to know (P.S. You also may be dealing with Noise Penalties since Puyallup is a Barrens).
For the Host: Rating and three of its matrix attributes, you can calculate the last one. (EDIT: I always forget about Grids, it might be helpful to know what Grid the Host is on).
Silent Running Devices: This might be a little more challenging. Succeeding on a test identifies that there are icons out there within 100 meters. Then it turns into a separate resisted test to see if you spot them which should reveal basic information (i.e. Gun Device Icon, etc) assuming they aren't also using the Wrapper program. Once you've spotted them, you can do normal Matrix Perception tests on those icons to determine additional information like device rating, etc.
Stuff Slaved to the Host: You would probably have to perceive the individual device icons to determine if it is slaved to the Host. Or (optionally) if you log into the Host, I would suggest you automatically spot any devices slaved to the Host since you are considered to be directly connected to them.