I assume I don't need to add in the FLP as an insured as it would be only a holding corporation.  

@Sherri Li You could elect the LLC to be taxed as an s-corp so that you would file an 1120s corporate form instead of being classified as a partnership. 

Just do what is average   You might to form some time  type of corporation or a LLC so you will protect yourself from others.  

What's least understood is that while the building tenant or upper corporate management located elsewhere may sincerely believe they're making the right choice in the best interest of the company to save money, in most cases, the end result leaves much to be desired whereby the tenant may actually be unaware of their having to pay more money in postponing the inevitable making an existing condition much worse than it is as time goes on.

I am a mortgage professional who just recently quit working for corporate (Loandepot) and become basically self-employed with a local broker office. 

I would like some feedback on which entity "LLC or S-Corporation" is best to use when flipping properties. 

I am an experienced investor and Real Estate agent (Licensed in MD and NC) that specializes in Short Term and Corporate Rentals - Please see this BP post about my first Short Term/Corporate rental development in NC: https://www.biggerpockets.com/forums/61/topics/385...I see a HUGE untapped market in the North Baltimore - South Harford County areas - Why arent more people taking advantage of the space that they already have in their basements/houses?

Many private investors and hard money lenders will ask you to close in the name of an LLC (or corporation). 

Maybe this will be the start of short term/corporate housing for one side of my new duplex.

Will depend on several factors like the type of property, type of tenants (for you, I suppose, people on the property), your risk tolerance, other assets you own, your estate planning, laws where the property is located, etc.Any lawsuits would be limited to the assets of the LLC and not your personal assets (assuming you run the LLC appropriately and the corporate veil is not pierced).