My property management is not equipped to report lateness with rent to the credit bureas.

Very specific tree saving measures must be done to make sure root zones don't get compacted by equipment. 

Who's equipment is he using to maintain the park?

Yes, there are costs in establishing, equipping, furnishing, supplying, and staffing a business that could be considered startup costs.

Even though my cabins are fully equipped for long term, I’ve never gotten a month long stays and although this is not impossible, I personally would never spend $3-4K (considering 1 bedroom hiuse) on a vacation in Big Bear :) not that I don’t like the lake so much, but for the money I rather travel to South America and explore mountains and have new experiences in Chili.Quick tip to get your calendar solid and the cabin more profitable: when you have those weird one day gaps between bookings, offer those to your existing reservations. 3 out of 10 people will stay longer so I just send them a money request and they pay for one more night at 40% off.

I am a big fan of laundry rooms, vending machine rooms, and storage go far.

Oh, I work as a photographer, and though I've never done real estate photography my skills and equipment might eventually come in handy.

My thought was to clear the back acre, cover it with gravel (or millings)  and offer machine/equipment storage until the proper time to build the expansion.  

I do not know much about you but sounds like your advantage is your construction knowledge and the equipment or relationships you have with that.

Equipment, furniture, and fixtures, termed "§ 1245 property", are tangible personal property.