Within a year my wife and I acquired four multi-families properties with a total of 20 units, and eventually another building to rent out (currently a bait and tackle shop) as well as an Ice House.

You can look at a conventional cash out refinance which uses your employment and income as well as DTI to qualify you...or if that is an issue, then I'd suggest a DSCR loan.

When taking applications, should I charge a fee to cover background, credit, and employment checks? 

However, when I attempted to contact her employer, she only provided an email address.

If you are currently employed, do not quit that job until you are 100% financially and can support yourself.

The loan is conventional and they are asking for Employment Verification saying I work remote in order to settle the occupancy rule. 

Employ and supervise my own construction crew.

Make sure you're performing credit checks, background checks, verifying income (calling employers and even checking bank statement if you need to), and calling former landlords to inquire about/confirm their habits as a tenant (cleanliness, respect for neighbors, paying rent on time, etc.).If you don't think you're capable of this, definitely find a good property manager!

You would want to employ strategies like 3 or more night minimums to encourage week long bookings and weekly discounts.I would actively adjust prices to maximize revenue. 

Are all employment sectors within the market diversified (less than 20%)?