Regarding use of miles: OneWorld partner awards and gift travel for friends. It provides a different twist to mileage runs!
Regarding value: 5 million annuitized for the rest of your life with a reserve for inflation adjustments would net, say 3-4% a year, or $150,000 to $200,000 a year or $75,000 to $100,000 per person per year.

Let's say you live in New York because you're rich and you can.

Round trips to Europe in J or F are between $6k and $12k. So I can take eight trips in F or fly once a month in J. This doesn't seem to be that bad a deal if you really had friends you wanted to hang out with all over the world for the rest of your life. It's not that much travel in any particular year, but I'm not sure how sustainable a lifestyle this is.

A not insignificant worry would be AA's financial health.