Real estate is unique that lending is so readily available to purchase this type of investment, however, leveraging is also a strategy available in the stock market as well.  

Beatrice,I chose in the end not to do a non-recourse mainly due to time constraints, but this man was very responsive when discussing options etc.... and seemed to have some unique long term programs.

In the under 30K range, one car breaking down, or one large medical bill may force the tenants to not be able to pay their rent. 

I have a good job that I don't want to quit until I can at least replace my income with passive income and I believe, by living below my means, I am in a unique position to fund my future real estate deals.I am in the process of buying my first residence (a foreclosure) that I will be able to make a profit on when I sell, and in the meantime, buy other foreclosures to flip and also to hold.  

In the 1990s, I worked in Risk Management and Patient Relations for 14 years at a large medical center.

However because we are in a higher tax bracket literally every penny of that money is going to taxes and increased medical costs.

I envision a community with pools, clubhouse, social gatherings, shuttles to nearby shopping and medical, "handyman" type services to help seniors with maintaining their homes and yards, someone who can run errands, etc.

I'm just now on the verge of investing, and my capital comes from 2 primary sources: employment as a medical professional for nearly 25 years, plus the great  appreciation from the house we used to own - but sold a few years ago to move here.  

I've worked in network for decades and there's lots of issues here.For the owner, you could provide a subscription service for each tenant & deny all other access, BUTif all tenants connect to your modem or router, you create a security risk for everyone.Pre-wiring would require a setup like:ISP==modem--router--- to units and this generates access from one unit to the other.for a more secure layout you need an extra router for each unit and someone to set a unique address for each router - - and this isolates each unit from the others.In either case, notice there's only one ISP so everyone has the same level of service and you'll need a big bandwidth to support multiple units. 

Your lesson above is tremendously helpful, but I think the reason people continue to post that question is that they feel their situation is unique and are seeking advice from experienced folks.