Okay, so I finally had to take a break so I could recharge my controller, LOL. I was having so much fun, I didn't even notice low battery alerts. If anyone here wants to know how it actually all works, and not the hyperbole/hysteria/rage, this post is for you. The game isn't perfect, nor exactly what I would have designed, but the amount of misinformation out there is absolutely incredible.
Full disclosure, obviously I purchased the Deluxe Edition since I am already playing, and got the pre-order bonuses (which you can still get, and if you are getting the game, they are neat - especially the skins). I also spent a whopping $5 Microsoft Reward credit I got on crystals (which was plenty for me to get what I wanted - I get those $5 rewards from MS once a month or so, and I could see myself using them again for "free", but I don't foresee feeling the need to ever spend any more actual money).
First of all, all of the trooper classes are unlocked to begin with. The only characters that need to be unlocked are some of the heroes. At launch, are 6 unlocked and 6 locked. Due to feedback, EA reduced the cost of these by 75%, so they are quite reasonably priced now. 10-15K credits. I already have two of the locked ones, by the end of this weekend I'll have them all unlocked. Once they are unlocked, they are available for unlimited use in Heroes vs. Villains, and become available in normal game modes via the "battle points" system (which controls how many are on the map at any given time).
Battle Points are not currency, they are points you get during a match and only apply to that match. Everyone starts the match as their choice of trooper class, and then as you play, the points accrue based on your performance (nice touch - they actually richly reward you for "playing the objective" and not just how many kills you do - if you stop someone from doing an objective, you get a significantly higher amount of them). Battle points can be used for heroes or other special classes that are only available as the match goes on, depending on the map/mode. When you die (which you will, a lot, just like the last game) you can spend those points to come back as the hero/special character instead of one of the base troops. Now, I'm admittedly rather terrible at shooters, but I get enough points to at least come in as a special character a couple of times per match (depending on the length), mostly because I focus on the objectives.
I'll be back a bit later on when I have some more time to talk about Star Cards/Crates and how all that factors in. If anyone has any actual questions about how things work, I'll also happily answer them - be forewarned, however, if it's "but how isn't XX evil" or asking me to defend this or that, or garbage along those lines, I'm just going to ignore it. I'm just here to give the facts from actually playing, and I'm sick to death of all the other talk and it isn't worth wasting my "breath".