Jade,
I refer to short term cash flow as investment where the appreciation is not considered at all and you look at the investment as dividend earning. The price of the house may go up with inflation but what is most attractive about it is that with very little investment, you can get a great monthly income. Long term investment for me is when you buy a property with lousy cash flow (Not necessarily negative, but very little income or none), but with better long term appreciation and better rental in the future.
The conventional wisdom when people talk about investing in real estate, is putting as little as possible down, taking a loan and leveraging on that loan. Mostly that means $50,000 and up since most conventional loan go for minimum $40,000. What I'm talking about is $10,000, $15,000 or $20,000 cash investment. If you are a handy man, you can get by with less. About a month ago I found a house for my contractor in a great rental area for $8,000. He spent three weeks working on it and he is putting it back on the market for $65,000 (With the money he'll get, he plan to buy two more and rehab them as well).
With regard to occupancy, that's is the beauty of buying cash. If I don't have a tenant for a month or two, the sky don't fall. In my "long term" investment, I have tenants that I hope won't move because there I do have mortgage, but that is part of the deal. The idea is to find attractive houses in attractive areas that people won't move. My friend whom I consulted with when I started, have houses in San Antonio, TX when his tenants didn't move for eight and ten years.
I cannot advise you on Multi-family since I don't own any but for me, it doesn't really matter of you own three houses that cost $100,000 each or a triplex that cost $300,000. 66% of occupancy would be the same for that triplex or those three houses combine.
.. And By the way, I'm an AD (Asst. Director)
http://us.imdb.com/name/nm0957306/
Good luck