You might consider doing a mailing to reach out to off-market leads.

I am trying to get access to the MLS to pull historical data on sales and find potential leads but am having difficulty.

If underwater, a short sale could be negotiated and (hopefully) a full waiver of any debt remaining on the loan will be obtained.

Might be the best investment to gain the knowledge you need.undercapitzlized investors have no business trying this stuff.. it leads to innocent sellers getting harmed..  

As long as the appropriate docs are in place with the lender (so you're fully aware of all the terms/conditions of the loan) and you have a verified exit strategy (refinance or sell at a price that would cover the debt), I would go with that option. 

The fact you don’t mention the strategy leads me to believe you already know it’s unethical at best and criminal at worst.

So it’s not the protection I was lead to believe...I appreciate the advice!

Another option is to ask the seller for seller financing terms where they carry the note and you won't have to worry about it affecting your debt to income (as calculated by banks).I think that it will be harder to really scale with only SFRs.

Continuing down this road will lead to nothing. 

With this additional debt added, it could break the deal, and the seller will let the property go to auction.