Multiple Soundcards

I have three (3) soundcards made by different manufacturers. The first is a pci card, the second is a pci-e card and the third is a usb interface. Would n-track studio 9 be able to work with all three simultaneously, giving me the total of their audio inputs/outputs? Can it do the same with their midi inputs/outputs?

With regards to their audio inputs/outputs, is latency the same across multiple soundcards?