On these loans, you don't put any employment or income on the application.

To add a bit of color to @Chris Mason's comments, you could likely employ a property management company, so long as you had the right, and intent, on using some of the days yourself. 

As landlords we still will be vetting our prospective tenants for income, employment and payment history among other things.

Additionally, the gain on sale (including depreciation recapture) generally is not be subject to self-employment tax.

Not sure your Grandparents employment or income status, but if they do not qualify for a traditional loan, even if they do, a HELOC on the Hawaii property will allow them to buy a property in Vegas with cash before the Hawaii property sells.

I am self employed basically as I run my own e-commerce business.

Also, on the refi, the banks don’t like self employed, so I’d have a hard time refiing.

In particular, I need a real estate attorney and an accountant (I'm self-employed, so I need an accountant anyway).

Employment is in New Jersey but planning to use fha on house in Pennsylvania job is about 1 hour away going to commute daily will I have a issue from the underwriter I will live In one of the 4 units 

And how great that is. but a vacation rental dollar is not the same as a long-term tenant dollar. 3% credit card charge, software, insurance that can be two or three times more expensive and may be hard to get, the industry trend for listing sites to charge a commission to the owner such as booking.com at 15%, the fact that vacation rentals require self-employment tax, Linens and cleaners and maintenance people who have to keep it perfect, every possible kitchen appliance and coffee setups add toilet paper and soap and everything else, up to 30% to a property manager. so maybe if you're lucky a vacation rental dollar is 75% of a long-term tenant dollar.