It also depends on loans that you are trying to qualify for depending on credit, experience, and other factors.

Really depends on the route you are taking as to market I'd suggest.

Depending on whether you use a "light-doc" program or a "full-doc" program, rates will change.

Really depends on what you are looking to do / what markets.

For hard money loans they only look at your credit score and assets and the property to in regards to purchase price plus repair cost and look for the after repair value.

For a 3 unit building with one unit as a commercial space/retail space I would use either a 7 or 10% vacancy factor and perhaps higher depending on the viability/business strength of the restaurant.

DSCR loans are based off of down payment, credit score and either actual or market rents so it helps to supercharge an investor's real estate goals and net worth.

Depends on the square footage of the house to begin with.

Michael,With regard to insuring the condo units, the amount of building coverage you should have on your policy depends on what parts of the building you own. 

This way, you can have passive income coming in from multiple properties regardless of where you are living at the time.Ultimately, the best strategy for you will depend on your long-term goals, risk tolerance, and level of involvement you want in managing the properties.