Two questions regarding setting up a podcast with Behringer 1202fx mixer and a dual channel compressor limiter gate
I have the 1204USB for a while a ended up throwing out the USB adapter and getting a Saffire PRO 24 Firewire interface. This mixer and the 1202 are great but if I had the chance I would have gotten the Mackie Onyx 1220i which has the Firewire built in. 

However I did manage to make the mix minus work with this desk. You need to listen and monitor from the desk but record from the computer. Next you bring the audio back into the desk via the line out of the comp and into the 7/8 channel of the desk. Leave the POT panned down and listen to the the channel in PRE and make sure you live monitoring is also playing out the PRE to the headphones (PRE never goes out to main). Looking at the PDF for the deck: http://www.behringer.com/assets/1002FX_P0572_M_EN.pdf  I'm not sure if the 1202 has PRE setting but without it, you will not be able to do this.