So that I can monitor myself with the headphones, play audio from my computer , play on the keyboard, and send all of this to the main mix on the studio monitors? Can I do all of this with only one device?
That would depend on what outputs your keyboard has, but I suspect that it uses a jack output. You can convert that to xlr and use an xlr input, otherwise use one of the line inputs.
That would depend on what outputs your keyboard has, but I suspect that it uses a jack output. You can convert that to xlr and use an xlr input, otherwise use one of the line inputs.