But if the mortgage company has "lost" the property you could rent it indefinitely as long as you paid taxes and condo fees. 

The taxes are indefinitely deferred into the new property.  

Those able to switch to the abundance mindset easily acquire many properties in great areas and the money they have out of pocket rolls back to them enabling them to continue to purchase indefinitely.  

I believe you have to live there indefinitely

That can be 3 years, 6 years or indefinitely for certain reporting items.For other non-tax documentation purposes, I am not sure there are any hard cut off dates, you keep things as long as the documents have foreseeable relevance.In this day and age I establish an electronic copy of all important documents and simply keep the electronic files indefinitely.

For various reasons I am stuck with this property as a rental indefinitely, so I ask myself what can I do to set it and forget it.

I just hate to give up a rental that is cash flowing with good tenants that plan to stay indefinitely.

When you sell an investment property that you bought with the intent to hold you can do a 1031 exchange and buy another investment property and defer indefinitely paying the tax on the gain.  

If this is a true buy-and-hold, you want to set aside a reserve that covers repairs and capex indefinitely. 

But as I said, they roll over to the following year and the same test is applied, in definitely, until the property that generates the losses are sold.