I am counting on it as much as I am counting on the WoD MMO ever becoming a reality: not at all.
If it doesn't eventually have a F2P option, I certainly will not try it. I'm not going to pay money to play a game I've never played.
Then I'm afraid you won't be playing this game.
What are the differences in terms of Galaxy and Economic (mining, trading) between Star Citizen and ELITE: Dangerous??
There are a lot of differences, but the most prominent one would be the level of detail that Star Citizen aims for -- and the resulting beefy hardware requirements to even play it with lowest settings.
Apart from that, since the differences are quite numerous (beginning with the game's focus) I'd suggest asking this in CIG's forum; they're quite open-minded when it comes to friendly competition; Chris Roberts apparently even pledged for Elite Dangerous.