Depending on your self wealthiness, you might ought to form some type of corporation or a LLC.You might ought to get some advice from an attorney and/or a CPA (or a tax accountant) on this matter.  

It really just depends on your own goals, if getting into the real estate business is a part of that.

But it really depends on what you're looking for.  

All depends on the property and tenant.

Cost is between $20 to $30 depending how much information you want.

What color you paint depends on your market and what you plan on doing with the house.

But this may not work depending on the design, as Chris T.

For example, Fannie Mae has no less than three different ways of calculating rental income depending on the scenario (one of which is [ Rent * 75% - PITI ] that is frequently mentioned on the forums here).

However, since both units are rented this would be classified as an investment property in which case your rate will probably be 4.00% to 4.250% on a 30yr fixed depending on FICO credit score.The maximum loan to value for a cash-out transaction (investment property, duplex) is 70%.Based on the information you've provided it doesn't appear the value is high enough for the property to be eligible for a cash-out transaction but you can still remove PMI.If you want to send me a PM I can run a complete analysis to see if removing the PMI will offset the slightly higher interest rate.I'm also licensed in CA so if you're looking to purchase a property I can help with that transaction as well.

Garden level rental rates are going to vary block by block and depending on condition/amenities.If there is a specific property you are asking about then maybe you would get more traction.