You increase rents every year rents aren’t dropping.

I put quotes because its simple but many people make it more difficult.

The available Labor force will shrink dramatically and the cost of services will increase for landlord and other industries.

Simple things like a branded email at your domain and a website can open a lot of doors. 

I've heard of people doing this, but you need to be rehabbing it enough to make it higher value so ideally you need to be purchasing something that needs some rehab so that you can increase the equity because otherwise you're not gonna have enough equity to pull out

These rules have increased risks by making it difficult to get rid of poor tenants that pay their rent.

Can not go wrong with a rental in Ashburn since the rents have increased so much. 

I just bought a lovely 8 unit last April that had been horribly neglected but have turned it around and done some cosmetic renovations and increased rents.

That sounds like massive renos (ie new floors, painting...).Yes as you acquire more properties, the chances of having multiple vacancies (no matter how leases are staggered) increases.

One of the things to watch out with mobile home parks is the increase in lot rent.