Security Light/Warning chimes in 10 to 15 seconds after I start my car. I wait and it goes away every time. This is something new. I do have an aftermarket system with no sub.

Generally that indicates the security system passed the start cycle, but failed after the engine started. The system is programmed to recognize that a fail in this order would not indicate a theft attempt, but rather would indicate a system fault. So instead of shutting the car down, it warns you that something failed after engine start and the system should be repaired...because a fail durring start attempt may be in the near future, and in this case, the system has full reason to believe the vehicle is being stollen and will not allow the engine to start.

When you put in the aftermarket HU did you use an actual converter unit to go from the factory harness to your unit, or did you try to make your own harness?

I used the PAC C2R-GM32R wire harness.

I think its the ignition switch. I can wiggle this when the main front bezel is off. I also notice 2 small sky blue wires coming from the ignition switch. I hope I can fix this myself....?