The more organized your data, the less you have to pay your Accountant to do your taxes.So no, QBS is not a requirement. 

I haven't gotten any actual data, but preliminary proforma suggests the property is under priced significantly based on the popular rules of thumb abounding on this forum, and has significant upside potential-nowhere to go but up really.

Getting some data points, as I am exploring the possibility of starting my own insurance company to provide "Default Insurance" - landlord is covered for 6 months if the tenant defaults.Any feedback?

Scott:If you are simply looking to analyse a property, create a budget or model cash-flow, then there are lots of spreadsheet templates available ... or, at least enough bits and pieces to get you started on building your own.If you want to keep the books of your business, then you will be best served to get a basic accounting package (QuickBooks, MoneyWorks, etc) even if you have only one property (at the moment).Ask your accountant if they have a preference as they will be more accustomed to importing data from certain packages into their system.

Just do yourself a favor and look at the NY Times Census data for Pottstown.

Keep in mind that because Google doesn't provide much keywords data anymore, an increase in your brand searches can easily be mistaken for an increase in SEO.

You'd look at historic patterns and owner/occupant profiles, we don't have enough data points to figure the probability but 1.2% of profit is an acceptable known risk by most standards. 

Realtor dot com and CL don't get the "income" data feed from our MLS.

Here's some data I retrieved regarding tax benefits Four ways that an LLC is taxed.

Do you have hard data for your local area to prove this assumption??