Bought pass (France). Useless... cant get reservations... to any location... on any day I try (2 weeks ahead)

For domestic journeys in France (that's what you"ve asked for), you may reserve jour trips here, too:

https://travel.b-europe.com/eurail-ge/en/booking-tgv#TravelWish

Even key routes are available for today, so I think there has just been an error with Eurail's reservation system.

To consider: You are just able to do a reservation for trains that need a reservation (TGV, IC) and for which a reservation is possible. 

If a station / connection is served by regional trains (TER) for which a reservation is not needed / possible, it won't be shown. So it's a good idea to have a look a the timetable before trying to book - there may be more options. 

If it doesn't work for a specific connection, you may also ask here before you get frustrated. Of course it's possible that trains are full. But then it's really sold out and not just for rail pass holders. But that won't happen two weeks before for every train / location.