I really don't understand the question either. The hub needs the 5v and 3.3v from the 24 pin connector to run the '485 chips and PIC, respectively.
Are you talking about using just the 12v wires from the processor or graphics card connectors to run a second hub? You could do this if the second hub has the 12 volt optional components, which are basically 5v and 3.3v regulators and a number of capacitors. If using the passive hub or if you don't need the DMX out, you could probably use one of the 4 pin drive cables to provide the 5v for the '485 chips, if you have more than the three needed for the first hub.
The big concern is making sure you don't overload anything.
If memory serves correctly, each pin in the 24 pin connector is rated for 6A and the 4 pin connectors are rated for 10a. You really need all connectors plugged in on the first hub if you have a lot of strings attached.
If you are Chopping off the processor or video connectors, each wire should be good for at least 10A, just be sure you have at least as many blacks as yellows.
A fully loaded hub can pull a lot of amps... If memory serves, A fully loaded universe with no duplicate addresses is about 42 amps, which is what the hub is rated to supply (2 pins x 6A on the 24 pin connector + 3 pins x 10A on the three 4-pin connectors).
RM