Unfortunately the 950, like a great many surround sound receivers and processors, is not designed to integrate readily with processors such as the expander and graphic equalizer you have. Since these outboard processors are intended to work with a line level input, using the preamp outputs (which will have a lower signal level) may give the processors trouble. Locating them in this position would also mean that they are in effect for all sources at all times, even when listening in surround mode - at which point the mains would be passing through the outboard processing while the center and surrounds would not.

What sources do you plan to EQ? You mention DVD in your post as one example, but wouldn't the DVD input be handled digitally to allow for Dolby Digital and DTS processing?