If the air filter is dirty it can restrict airflow causing it to "run slow".

Other than that, it's Fairlawn Heights, Wallhaven, and Highland Square.I'm personally not a fan of out of state investing in Ohio.

I explained to the lender that I was using Business Credit Cards for the down payment, and that I was just acquiring them (there would be restrictions as to cash transfers for a period of time).

I am trying to qualify for another multiplex and have been told we can not use the rental income from the other units to qualify...? We currently live in one of our multiplexes and are looking to rent out the unit we ...

Open rafters will allow more sound to come through and you won't gain any ceiling height by removing the drywall. 

Rents and thus your income is directly correlated to crime rates, school zones, income levels, education levels, appreciation rates, rent restrictions, etc. 

Some states may have restrictions on how frequently or how much notice in advance you need to provide when walking a property.

Also depends on the type of loan residential loans are a little more restrictive, typically speaking then commercial loans.

The house claims to have a full height basement and is 2,600+ sqft in total.

Theres no way anyone is cash flowing in that area that has bought at the height of the market, or likely even now.