Install some random things? I know, I know, you don't want to hear about why you shouldn't do this. Well, I'm going to tell you anyway, so if it's only going to tick you off, you'd better click the 'back' button right now.
Let's say you get in an accident when a passenger is in your Jeep. Let's say the passenger gets injured. Your insurance will have to pay for their injuries. Except that insurance companies don't like paying for anything if they don't have to, and they all have teams of lawyers working on every case to see if there's a way they can get out of it. In this case, you've given them the perfect excuse for denying the claim.
Removing the driver's airbag for off-roading is not a good idea, but it's not completely stupid. Removing the passenger's airbag, though...