You'll need to ascertain *how* you show them that value/price gap or how they will show it to themselves.

It's been owned by a 90 year old woman who lives locally (and owns other properties from what I can ascertain.) 

For a SFR, you are  using a variety of data sources to get the comps for an area (such as market price per sqft) but with a multifamily, you are not necessarily looking at price per sqft  or "like" properties per se, rather you initially have to determine the rental price & cash flow per unit from which you can then work backwards to ascertain or derive value.Also, unless you have a property under contract, the opposite of attention is what you are typically looking for in regards any deal so you may want to learn as much about ARVs as you can -- fast!

However, these properties generally have a lot of land improvements that qualify as well as certain portions of electrical, mechanical and plumbing that can qualify.

If it’s the other way then they plan on bumping rents aggressively and you’ll want to dig in there.When evaluating financial projections of any kind it’s important to ascertain the assumptions that were made.

Where title is transferred as certain amounts have been paid, say when 25% equity is established in a property and each property is viewed as a seperate transaction, properties being placed in line to be purchased from one payment stream.You didn't say if there was any underlying mortgage on the properties.Another issue is that a MH park is usually under on legal description, so dividing each one out is not practical.

I know all this off the cuff crunching may seem humorous but I"m just trying to quickly ascertain how good of an idea it is to invest in rental properties with the main idea being to passively maintain a middle class living? 

To begin, I'd like to find one or more good (& hopefully) quick methods to figure out what that standard is after ascertaining which neighborhoods to focus on.I have a varied background, including computer programming, and my husband has been in the business of healthcare providing.

I've looked at Florida (because after this miserable Winter, that's where I'd like to hang out 4 months a year), but because I'm not that familiar with the state (I've lived in the same area my entire life), it's a bit of a challenge to ascertain what the strong rental areas are (beyond seasonal rentals, near the attractions).

The risk involved in possessing an abandoned property is controlled and mitigated by diligence in ascertaining whether the property has in fact been abandoned, why it was abandoned, and whether heirs are likely to make a claim.