Exposure is going to be the best thing for you at 18.

You could always call it a bonus room or office and let the renters do with it as they choose. 

That much exposure to the underlying business they might prefer equity upside of the franchiser.

The treasury dept and IRS just released the final set of regulations for the popular 100% bonus depreciation schedule.

The actual location close to the park is a bonus.  

You'll save a ton of money and gain invaluable landlording experience while minimizing your risk and exposure.

Bonus Question: Would you recommend in the future going in with partners with all our own cash (Splitting equity, but no hard money fees) or using hard money and being sole owner of the property but paying fees?

My understanding from my lawyers and accountants was that difference between an LP and LLC (with partners) is that in an LP, the limited partners aren't required to be on a note or title, hence limiting their exposure to liability.

There are many bonuses available for business checking accounts that get reported as interest income. 

Also if you don't get a bonus one year, they wont count bonus income until you have it for two years in a row again.