The remote starter I bought has a negative input hood switch that is required to be hooked up. Can I just hook this to ground and not have the switch since it's negative input?

 

you can put it to a ground, and it will always think that the hood is closed, so it will be able to start with the hood being open. There for defeating one of the main purposes for the hood pin switch. The other purpose is to let the alarm know that the hood has been opened while the alarm was armed. Run a wire out to the car, and tap into it directly at the hood pin switch on the drivers side. There should be two wires a black wire which is the ground input, and a colored wire that is youre negative trigger, connect youre hood pin wire from the alarm to the colored wire at the hood pin switch.

 

Agree, your car already has a hood pin switch. Why not just use it?