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. 

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).

Great idea(s) depending on your market. 

Therefore, your long-term income depends on the city's ability to attract new companies.

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

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. 

Depending on the state, when someone rents for a certain amount of time, usually 30 days or more, they become long term tenants in the eyes of the law, and they acquire "tenant's rights". 

It all depends on the state.

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