Can we park there for 15 nights without staying overnight and what would it cost?

Talk to Mgmt, the lot is usually full.

You can park for $8.56 per day. There is no maximum amount of days.

I would assume not. If extended parking is available it is usually on the website.

Park and ride is actually cheaper and transport to and from airport better

I don't know if you can do that. I really don't it. It would take up their parking for business.