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.

Depending on your market and the types of leads you are targeting, you will find some things work better than others.

It obviously varies by property condition.

AJ Golden IMHO, that depends on what kind of income, "line of credit," insurance deductibles, and risk you can handle.

He owned his previous property in his own name.The answer is "it depends." 

Also depends on if the terms from the seller is really good or not.

Depending on your financial position, you may be able to do both SFR/condo and try a small apartment through refinance of existing properties and/or the use partners.  

As far as how many to buy it depends on your goals.