This may depend on your market, of course, but in general, if all of the nearby MTRs have it, you are going to want it for your units, as well.

Regarding evictions, it depends on the time and resources you have available.

It all depends on the state.

It depends on a lot of factors; primarily the local jurisdiction rules that may limit lease changes (in Portland/Oregon rent, security deposit, screening fees, an no-cause evictions are heavily regulated).

It depends on the type of lender, the broker is using.If a broker is using a wholesale lender, they make their money on the back end side.

There's many other options in real estate such as syndication and note investing depending on your level of involvement. 

You generally would find that depending on what deals you have at the other end of the table best helps decide this answer.

Looks like anywhere from 6k to 10k depending .   

When I looked at prices recently they look like they've gone up quite a bit but I know they vary a lot depending on the neighborhood. 

Great idea(s) depending on your market.