No matter how air tight the lease, every landlord has been stiffed the last month's rent at least one. 

I’m not getting the issue with the dryer vent.....are you saying air going thru the vent on the outside of the wall a certain distance from your exterior bedroom window is going to cause a noise issue for you, inside?

Before you know it, you'll be testing the paint for lead, the water for arsenic, the air for mold spores, pulling up the subfloor to determine the radon seepage, raking the yard looking for poisonous snakes and camped out with a flashlight and a machete in the yard in the dead of night warding off the threat of a zombie apocalypse while they chat up your other tenants into a class action suit to address your "negligence."

I hear a lot of investors are using the Air BNB strategy.

What caught my eye was your comment on moving up in price to move into more 'rare' air in terms of less investors.  

If the existing lease does not have the language in it that allows for that kind of extra expense (which is probably unusual) that makes a tenant partially or fully responsible with explanation to the new tenants responsiblility for that type of expense for air conditioning that is unusual unless common in that area and might be discovered during the research period on the subject property and uncovered then. 

I was curious if anyone in the Baltimore area (more specifically in Abingdon/Bel Air) has experience with buying foreclosed houses and renting them?

Just want to clear the air that I have absolutely no association with them, lol!

Towson is getting a breath of fresh air with the redevelopment of downtown Towson, and I personally believe that Towson will become the center of the entire Baltimore region in the future, simply because Baltimore City will never not be a crime infested hellhole.Anyhow, enlighten me, what say you?

Cash flow is not negotiable, you need it like the air to breath and it pays your bills, but it does not create any significant wealth.