If you get a DHP powertuner your vin won't matter. If someone is local with a tuner thy might be able to help you read your PCM and check if it is modded and verify the vin.
As for the HUD my guess would be a loose connector related to the speed input to the HUD.
And running the tire above psi isn't really a safe thing to do. Have you tried getting the tires rebalanced? Vibration at hwy speeds is normally just a balance issue. If the tire is ou of round chances are the belts have shifted or damaged. If that is the case get a new tire.
