I wanted to see if anyone has any good recommendations for licensed contractors in the Essex County NJ area?

You have to be very clear with your Landlord, get it in writing, ensure the home is zoned for short-term rentals, and get the property insured properly.

I have been debating on where to get my real estate license.

Posted from the phone app and it did not give proper paragraphs making it a bit tough to read.

I got my real estate agent's license a few years ago as a way to get a feel for the market, and I emphatically agree it is a tough place to start!

You should ask for the leases and read them to see what exactly you are inheriting to better understand what you are on the hook for.As far as the past due rent, not sure why the owners think that you should be on the hook for them not enforcing a lease agreement properly, but maybe you can make a deal with them that passes on the $200 per month as long as he pays it. 

If you analyze properly, and buy based on that analysis, any "downturn" should impact you less than others, and in fact, set you up to be empowered during that "downturn".The Risk Controls you put in place, and follow, for the "upturns", should have the same control during a downturn.

Do I need a business license to operate rental units in central Florida? 

Short answer, if the HOA foreclosed and now the mtg holder is foreclosing, you will indeed get proper title. 

Also I hope to be licensed in the next month.