not much to say. The monochrome switch can be used to create (I guess) black/white image and free up other circuitry for more patching.

Video driver op-amps are needed to drive such high load (2 * 75ohm). I plan to use the LM6181.

For the processing part of the signal, no need for high current output op amp but they need to be high speed nonetheless. I plan to use signals that go at least around 1Mhz. So, slew-rate and bandwidth are essential.