|I use a 12-channel, 4-bus mixer in my edit suite.|
In addition to allowing me to choose from a number of audio input devices, I also use my mixer to feed the speakers in my edit suite. This means the mixer is set up to send an audio signal to the input of the edit system as well as accepting the audio output of the system.
|Send ALT 3-4 to CTRL-R.|
As long as the mixer you have has more than a single bus, you should have no problem setting it up so that all your sources as well as your edit system are sent to it without the risk of feedback.