Ok so heres the story;

My buddy and I were re-wiring my sound system when he decided to attach the positive cable after the negative one to the battery. Sparks ensued, and then when I started my car to ensure all was well, every possible check light on the cluster was on and stays on even with car off, no gauges work and the cluster lights dont come on. I removed the cluster fuse so my car doesnt drain the battery on me. So I figured I had shorted out my cluster somehow and was going to replace it until i noticed if while the car is running and headlights/cluster knob on, i hold the power unlock button the lights and gauges all work. Very confused lol. Now im thinking it may be the switch knob that is fried.

Any thoughts welcome. thx

The main reason to connect the negative AFTER the positive is to prevent shorts/fire if your wrench happens to contact the body of the car while tightening the positive terminal. Otherwise, it really shouldn't affect much of anything. The sparks were likely just from the capacitors in your sound system charging rapidly when the connection was made.
If you haven't tried it, just disconnect the battery again for a few minutes and re-connect. Try to ensure that once the terminal makes contact, that it stays contacted. Hopefully this will allow things to reset and work again.
You may want to remove the fuse going to your sound system while you're hooking up the battery, and the carefully install it afterwards. Maybe some strange voltages from the caps in the amplifiers bothered the cluster or BCM during the original connection, so this may reduce the chance of it happening again.
Really this is just a guess on my part - but it's what I would try if I experienced it myself. Fortunately for me, I haven't seen this one yet...
John