I notice that each 4 Pin Molex Connector (coming out of the power supply) has a second one attached (which is longer), can I plug in two separate components for each 4 Pin Molex Connector on that same wire?
Typically, yes. Usually the draw on any component that you would use to make those connections isn't enough to cause any problems with connecting to both on the same wire. Some larger PSUs have even more of those 4-pin connectors on a single peripheral cable than two. I have setups where I utilize as many as three. What I don't suggest, however, is that you connect all your components to one peripheral cable, and leave another one empty. Try to balance the load. I'm not going to go into details, as it involves the actual electrical design of typical PSUs, but just try to put as even as a load on as many cables as you can - it can save some headaches or the length of life of your PSU.
