"how likely is it that I will get to know every single card and which objective they are associated with, and what they do, when I have to know my own deck?"
This is exactly how the winners of all the tournaments are going to do it. It's just like people counting cards at Casinos - only much easier. That's what I would do.
The thing is, even if you knew every single card your opponent had in their deck, it still comes down to how you play the cards. Do you want to keep Vader in your hand to deploy this turn, or keep him in your hand and try to bait your opponent into an attack where you can use his 4 edge dots to bluff him into thinking you're not going to respond with anything too strong?
There's a lot of situational things that can come up where you can play the same decks against each other several times and still have different outcomes based on luck of the draw, and taking calculated risks against your opponent's play style.
Added to this, for a Core Set, you're not going to have too many options anyways, but I doubt it will play poorly out of the box.
I'm not sure how long we will wait before the first wave of expansion packs come out, but if you're fortunate enough to have a big competitive scene in your area right at launch, you're all going to be playing with the same tiny pool of cards for a while, regardless of how you build your decks.
Compare to the Netrunner Core Set, which had a tournament last weekend. Sure, you can pick an Identity, and with the Corp, have 4 factions to choose from to mix your cards, plus neutrals. Without having it all in front of me, I'd imagine that while many combinations are "possible", not all of them would be "viable" at a tournament level if you were playing to win.
I'll wager that bluffing your way through an edge battle becomes a vital part of the game, when you consider that the same powerful cards you would want on the table will also win you an edge battle, but which way do you go with it?
In the example I gave above with Vader, let's assume that in the Objective set that he is attached to, you can have two copies of the Objective in your stack, and thus have 2 Vaders in your 50 card reserve deck. (60 cards total: 10 Objectives, with 5 cards belonging to each; 10 Objectives, 50 "player cards")
So lets say you draw out the top 3 cards on the Objective Deck, and you get both Vader Objectives, so your opponent is thinking "oh noes! 2 Vaders!!!1"
At no point will they know exactly how and when you're going to deploy him, if you ever do at all. He could be the last two cards in the stack, he could be used as an edge card, he could come down on the ground the first turn, or be held back for "just the right moment" later on.
A good player will take note of the possibility and be aware of it in their decision making process for how to play their own cards, but it won't guarantee anything critical, in terms of having a huge game advantage.
A more inexperienced, or unaware player may not connect the dots and eat some kind of Vader beatdown, but then those same "noobs' can surprise you by doing something nobody in their right mind would try (which is sometimes why it works). But then, if you're the best Star Wars LCG player, would you be spending all your SWLCG game time carving down new players, beneath your skill level, or would you try and teach them the ways of the Force and help them game better, assuming that was their goal, and not to just have fun playing cards as they feel.