Yes to the first question. As for the second, you may be able to do something like if you strangely connect things to work off the relief off the valve, however you won't independent control of anything this way. The defining factor is the number of positions the solenoid can be in. The ones I was talking are all examples of 2 position solenoids, where there are really only two useful outputs. The relief ports are where you might put something like a flow control if you want to vent slowly, or stuff like that.
Here is a document on reading the schematics.
Here is a site talking about the principles behind the operation of a solenoid valve.
And yes, this forum is absolutely open to everyone and anyone who wants to talk about anything. We're more than happy to help out. However, as Eric said, it will be dominated by FIRST robotics participants talking about robots. In this case, and in many others, your solenoid question fits in perfectly.