>> Anybody thinking of taking this flight needs to google: blood clots, pulmonary embolism and long flights <<
Been there, done that.
Just take several aspirin, drink about a gallon of water, avoid caffeine and alcohol, and don’t remain seated for more than three hours without walking around.
Then you’ll be fine — no clots and almost no jet lag.
If you drink a gallon of water you won’t remain in your seat for 3 hours. You’ll be up walking to the loo.