Even if you don't cash-flow, they can significantly reduce your mortgage payment and allow you to store extra money away to pay down debt or save for future investments.

Like for the national debt, or the future (in)solvency of Medicare/Social Security/pensions?  

Since credit then becomes more expensive, less expensive credit to the debtor is more valuable and is held longer.  

@Michael Lauther So will you use the 401k like debt or can you use it like equity and then get a bank loan and essentially be 100% levered?

If it has been ordered by a judge, generally the foreclosure will be expedited or the debtor may deed in lieu.

Liability (I have this threw my property insurance) and LLC (Which does depend on your state): I like this NOLO source of data, its fantastic:http://www.nolo.com/legal-encyclopedia/llc-asset-protection-charging-orders.html Some gems from this article "All states allow personal creditors of an LLC owner to obtain a charging order against the debtor’s LLC interest.

I have no other debt or other significant income sources.The above properties are all in Plainfield, NJ.

Interestingly, he listed the other defendant (his wife) as one of his debtors.  

Any government action that reduces student loan debt or makes qualifying for a loan with student debt easier will drastically increase the demand for middle class homes.

If I can negotiate with the seller to take over the debt or terms for a master lease or subject to deal, great!