It ties into your great grandfather’s troubles during the 1932 depression; your grand parents ability to purchase a home in 1953 for $100 down with a VA loan, and your own psychological well being at having to have a percentage of your income going to pay debt each month.However, unless debt is so debilitating to you that it keeps you up at night and inhibits your ability to make rational decisions, the decision to pay off debt early is merely a function of numbers.  

You will get a donation deduction and fill really good.

My parents actually have land in the area from where our rental properties are so we have moved it there.

To much money left over-  so you set up your trust and have money designated for donations, have your lifestyle covered, no kids, no spouse.  

Or, if they sue both the LLC the property is held in, and the parent LLC, would it open up exposure to other LLC's owned by the parent LLC (i.e. other property holding LLC that I have?).

@Jacky Peng I'm trying to convince my retired parents to do a garage ADU conversion out near SFO airport where they live so please keep us updated here on the forums, I look forward to hearing how this all goes for you and what other questions you have along the way!

I would not look at it as altruistic though you can donate time money and houses to charities  for that ..  

Often nicknamed a "Kiddy Condo Loan", it's a great way for parents to get a property for their kids as a primary residence.Regarding the debt-to-income ratio, that is a genuine concern and something you would need to consider. 

We need a larger home for our family, that would be functional for multi-generational living with our kids and our parents living with us.

Some people come every year near same time whether snowbirds, for parent/child birthday, or simply because they have a favorite time to book.