Another twist will be to have a mix of long term rentals away from the tourist attractions and vacation rentals close to the beaches.I am looking for advise, tools, samples, insights on how to best create a business plan and identify the best tools (software/apps) for the establishment of this new company.

I got all 72 units set up with tenants as sub-customers (I found out by calling tech support that on the desktop version, they are called "jobs" rather than sub-customers, but does same thing) as you said and it looks like it is going to work great. 

Charleston is the only municipality in SC that builds both cars and planes, we have non-stop flights to London, and our tech sector is called "Silicone Harbor". 

The Metroplex proper has mostly tech and other professional type employers plus a bit of heavy industry and defense contractors. 

The tech says the compressor is gone bad , unit is too old and says it needs entire unit replaced a AWUF Airhandler and GSZ13 heat pump, Looking for some quality HVAC tech references that could help me diagnose the problem properly and fix the part rather then replace the unit.

We are looking at a duplex in a town that is known for a high crime rate but the street is a family street with a mix of single family and duplexes.  

Many here on Bigger Pockets would say that they are diversified because they are in a mix of properties in a mix of markets.  

There is a vast amount of knowledge mixed in there and they can help you find what you are looking for. 

I've jumped into the mix and am swimming after my piece of the pie. 

I have heard some mixed reports from my bankers this week an wanted to know if BP could shed some light We are wanting to buy a 79 single wide mobile home with a lot and a nice 2 car garage.