The majority of lenders require a 6 months seasoning period.

For a long time this was not the preferred way because of the short holding period. 

You can bet on your tenants being in place over the next year and that cash flow coming in over that 1 year lease, but you can't be sure how the stock market is going to perform over that same time period. 

You will have to intend to live in it for a period of time over the year.. but the rental income that you mentioned to them will most likely make them say it will need to be reclassified as investment home.FYI- loan level pricing adjustments on second homes are changing April 1st this year which means rates are going to go up on a second home (pretty dramatically actually).

My advice is to make some offers and use your brother and the due diligence period to make your final decision. 

During your due diligence period you should be able to request that the seller provide a trailing 12 month breakdown of the expensesAlso, 30yr fixed is a great product as many mentioned... my thought is, take the lower payment, then if you want to pay it off faster you have the option.

Working through my identification period on my 1031 exchange.  

But there is no statutory holding period  only your intent and how you can demonstrate it.Converting from investment to primary doesn’t create a taxable event.as long as you own the property you’ll never pay the tax!  

I am currently 65 yrs old and I am wondering what would be the best tax strategy to remove those 3 property's over say like a 5 yr period. 

Besides a “ hot” 3 month rental period you need a warm additional 6 months to make  above average returns.