The next time some non-landlord posts in this forum about how bad low-income -housing fixer slumlords should feel for taking advantage of our C/D-class tenants, I'm going to try not to jump down their throat, but no promises. 

hard money is a loan not cash even though the quick close times make it appear as a cash offer 

It's the promissory note that contains the promise to repay the amount borrowed. 

I'm not looking to get rich quick, just to build a real estate portfolio to supplement my military income so I can retire at a young age.

This is my experience from Hurricane Katrina now 13 years ago:Properties in nice neighborhoods were available at hurricane sale prices for cash buyers.Fairly extensive rehab was required but 13 years later those properties are now worth 2 - 3 times purchase + rehab price.Not a get rich quick scheme but for those with cash and patience it was a once in a lifetime (we hope) opportunity.

Quickly accessible.

But what else do you need to do to make it livable, to make sure your properties rent out fairly quickly (good tenants), and to make sure you're being a great landlord?

I can practically bring in tenants after some quick and basic fixing such as the roof, painting, carpeting and new windows.

., I know you're starting out shallow but this could turn into the deep end of the investing and 1031 pool real quick. 

@Brian, and that is a perfectly reasonable position to take, in my situation I'm in NYC, a very tenant friendly state, it's not unknown to be tied up in court for a year trying to evict a bad tenant, it happened to me, took eight months to get him out , situations like that can quickly mess up a positive cash flow, if I had a mortgage on that property I would have been in bad shape.