#1
Hi,

I have a problem with my Behringer electric guitar, the TONE knob broke off and it seems like the metal thing that was attached snapped, am I screwed?
#2
No, it's just the potentiometer that the knob turns. It's a cheap part, $5 or so. You'll need a soldering iron and a screwdriver to replace it. If you're not comfortable with those you can take it to a guitar tech who should be able to fix it for you fairly cheaply.