I've read some articles on this, and it appears to be accurate.

It’s not going to be perfect, and would just go off general averages, however, ai highly doubt those averages are refined enough to get down to niches, such as a home on the lake vs a home four or five blocks away will likely have vastly differeing occupancy rates.I use its general averages as an indicator of whether or not I want to even bother with an area, if I decide to I then go in and find direct comparable homes and gather data from those ones specifically to create a much more accurate projection. 

That is not 100% accurate also because it is often done by a third party company who does 'drive-bys' to evaluate properties.

@Guy PrimoFor an accurate account of the 1% rule that includes a HOA expense you need to add the monthly HOA directly to the calculated 1% rent.

If that's all accurate, I'd agree that you're entitled to keep her security deposit to cover unpaid rent for the 30 day period she was required to provide notice, OR until you find a new tenant and that tenant begins paying rent. 

Definitely talking to a professional is your best route as they can accurately run the numbers against all options you may have.

Sometimes accurate vacancy numbers are hard to get unless you ask for a detailed T-12 or annual RR, and then figure out the vacancy rate yourself.

@Andrew M Bickett because your expenses are not accurate.1) 8% is their monthly management fee, but they also charge a placement fee, which is likely, at least, one month's rent.

On the plus side, their online system is pretty good... all documents properly loaded, reports of who paid and when are accurate and the money is forwarded in a timely manner.  

More sophisticated contractors use various bidding software to get the most accurate quote as possible.