Welcome! Performance upgrades so far mostly exhaust (catback), springs, brake rotors/pads, a tune, maybe a cold air intake. More options for the engine if you have a 3.7L (since it is shared with the Mustang), and coming up if you have the EB engine (tunewise). Body kits, nothing people have really liked so far, most interest has been in mud flaps and side skirts. Electronically is where the door is WIDE open: audio/video, lighting, etc.
Have you had a chance to drive the Lincoln MKX and compare audio systems with the Edge? If so, impressions?
Post some pics of your Edge, and your work in progress