Ari

Yes, worth it. But important not to do it during rush hour, otherwise you can't really get that fast. Also, hard to stay under the 150km.

Jet lag has nothing to do with it; all it has to do with is how well-rested you are. I slept for 5 hours on the way over (new 744 F); that's a pretty normal amount of sleep for me. So what if it was 4am in the States? I was wide awake after a good night of sleep. Now, if I stayed up all night on the flight drinking and watching movies, that would be a different situation.

Depends on your flights; a glass or two of champagne 7 hours before your drive doesn't hurt anything. 2 hours before your drive I wouldn't recommend.

They have their own recommendations on the website but frankly, you can just ask where to go at the counter when you rent the car. They are perfectly aware people are only doing it for fun to reach high speeds. I think that is the point. What else can you do in 3 hours?

1) Probably not. Seeing as you are not entitled to use the FCT, why would they let you use the services of the FCT (i.e. the valet service)?
2) What possible purpose would that serve? You drop it off at the FCT only then to walk to the terminal? Most people walk to the FCT from the terminal, not the other way around. Wouldn't it be easier just to return it in the terminal where you rented it and go to the B FCL from there?

FWIW, they didn't bother asking for my boarding pass at all. I'm guessing they aren't all that strict about it and arrival is fine.