[Jeph]

Welcome Lordblood. What a pleasant moniker.

It will run on 87. It may throw a check engine light. But think about it. It's about $4 dollars more per tank. That's a pack of cigarettes, a small fast food meal, 3-ish songs on iTunes, a venti latte -basically, a small price to pay to ensure your engine is getting the best juice possible. If you can skip any of the things listed above (or some other $4 vice) per tank, do it.

But, if you still rather save a few bucks and take a chance with that check engine light, make every 4th tank premium.

As for your airbag noise, that's new to me. I wonder if it could be some relay or something. Could you describe the noise?