They can also be great for situations where you are looking to secure a property with more conventional financing, but don't have enough time to close with the original financing.

Sometimes if there isn't an agent involved (or an agent that isn't properly engaged) the software will use incorrect assumptions due to errors in public record and available data. 

How are people holding security deposits in NC?

As a public service I'll share my pre-biggerpockets experience with one of these "100% lenders" I attempted to use one of these lenders, Quickfunding LLC out of New York.

Security Service FCU use to do a 100% LTV HELOC in UT and CO. 15 year draw 25 year payback 40 year loan.

I do around 60% direct bookings and have a few steps to help establish against chargebacks and fraudulent charge claims. 1) We use Stripe to process payments, and they have a pretty solid fraud system.2) We use chekin.com to register guests to make sure they match the credit card. 3) We don't take day of bookings 90% of the time. 4) charge a refundable $250 security deposit5) you can also use something like Superhog or Safely for damage protection.We also have a rental agreement, which you can have written for you by a local real estate attorney.

Put up signs to let them know cameras are in the area and let each tenant know that you put up cameras for extra security and that they are only in common areas.

It seems the accountant was highlighting that a CPA (Certified Public Accountant) can represent you before the IRS, while someone without a CPA license or Enrolled Agent (EA) status cannot.

Notes are not secured by any collateral or guaranteed or insured by any third party"

Insurance doesn't want to hand over money sometimes even when they are obligated to, that is why public insurance adjusters exist.