Fuel questions

[Lordblood]

Hi there! I'm a week old Porsche boxster owner now, I bought a blue 1998 Boxster and I'm loving it so far! Fun to rev!

Anyway, my question is, is it ok if I use 87 octane fuel for my Boxster? I realize it would drop performance, but I can take that, I put in 91 octane a few days ago, and it's doing fine so far.

Also, when I turn the key and leave it where the engine isn't turning but the battery is on, I hear a noise from the passenger airbag section, is there something I should be worried about about it?

Thanks for your help everyone!