That may have health consequences for your residents years down the road(recent research shows.) 

Why not try to approach the owner and buy the property first, you cut out several steps and a lot of time that way and then there is no possibility of the owner bringing the loan current and leaving you stuck with a note which it appears you don't really want?

I am using the Rental Calculator (in Bigger Pockets) for a several unit purchase (SFR).

There are several ways to get in contact with these owners - I suggest mailing or calling owners to start out.

I assume that if I go through the real estate agent course and exam, that I’ll have several advantages as a new Investor:1.

Had I known there was a tank I would have a) not purchased the property (I passed on several properties because I didn't want to deal with an oil tank) b) had the owners remove it at their expense or c) would have asked for a significantly discounted purchase price to account for the risk.

But if you have several applicants meeting your criterias just pick the one you met and felt he/she would be a good fit for your property.

@Peter BechmannThere are several of us who work with clients all over the country via electronic communication.

I own a commercial space (business condo)I used to operate a business in the space, but several years ago sold the business and leased the space back to the new business owner (about 3 years ago). 

This would be a good place to start.There are also several QIs here on Bigger Pockets.