FanofTristars: ER-1181 travel certificates can be either Space Positive or Space Available. There is a spot where it is checked off on the certificate. If you've already got the tickets in hand, it should be marked accordingly. At the very least, one diagonal line means Space Positive and two means Space Available.
If it is Space Available, I'm afraid you're pretty much at the bottom of the priority list, as they go on the list at "S8" which comes after employees (S4) and buddies (S7). There is a chance you could have an agent that doesn't know, however and puts you on the list differently.
Kjet: As far as US' service, I've flown many times as both non-rev and paying passenger. It's quite good in any class and yes, the A330 entertainment can't be beat.
Arriving in PHL on the ERJ will put you at terminal F, which requires a shuttle bus ride to terminal C where you then have to walk to terminal A for the Paris flight. This will give you a good overview of the facility from the inside, and should take at least 15-20 minutes under normal circumstances. You remain in the secure area the whole time. PHL is prone to ATC delays and the runway/taxiway configuration makes ground congestion a problem during peak times, however if the weather is good there should be no extensive delays.