I currently have a TSL 100 Stack and recently bought a GNX4. I have a few of questions because i go by the book it gives you and can even get sounds. And no that doesnt sound stupid to me. Somethings is going on and im not happy

Can you run the mp3/drum/midi tracks through the amp?
Or Can you plug directly into speakers?
Can you only use the headphones if your plugged in through the XLR sockets. I want to just plug my guitar straight into the GNX4, strap the headphones on and play?

Anyone for suggestions?
Maybe a website to go to?

THanks a bunch if you post