Great Game Guarantee gives 7 days post-launch to refund for pre-orders. I don't know about others, but that makes me feel fine with all the let-downs of expectations coming out right now. especially since I know I've been let down by EA/DICE in the past.
I was really disappointed by the BF4 launch. I played a lot in the first two weeks before I decided I was done waiting for improvements, and the game was released far too early, and didn't properly meet the specs they advertised. That's when I finally lost faith in EA/DICE choosing quality over release schedules, but I didn't have any refund option except for a chargeback--which I've done to EA in the past with BF3 (resulting in a completely online-banned Origin account), but that was an entirely different, justified decision; not liking the game and not considering it finished wasn't a good enough reason. I knew I didn't get a refund guarantee on this one, and I just got to excited, and made a bad purchase too early.
The refund guarantee makes me feel a lot more comfortable pre-ordering, and will just make me stricter in taking advantage of the refund in the first week of release. After BF3 and BF4, I'm a lot wiser to EA/DICE's methods to know what to look for in launch to see if they really are just pipelining sequels, or are actually learning lessons. So for the first time, I actually feel okay with pre-ordering. I'm not doing it yet, but it's a big show of faith in their production compared to BF4 release.
As to your demands...
I worry that forcing demands like this on the production of the game at this stage will result in a much worse product, and I think it's a futile attempt anyway. It might just be a sign that you don't want the game because your ideals weren't met, rather than demanding reasonable ideas get squished into an already ambitious game. They're letting you down early, so you can get over it, or lose interest. A boycott seems a little extreme for features like you're asking.
It's a disappointment, but changing from rails to free-roam--especially at this stage--doesn't seem like a simple undertaking by any measure, and the other demands are even larger undertakings. A full campaign is an entirely new production, and we're far beyond the era of AAA titles with top notch SP and MP experiences. I don't see it happening at all, but if somehow a pushback like this is successful, I don't see EA/DICE as capable of launching changes like this at this stage without totally messing them up, and I think they know that, too. We'd just be even more upset at launch if they cave to demands like this and break the game trying to rush it in.
Oddly enough, I actually appreciate them simplifying some of the more ambitious ideas people naturally want to see, to focus on the core of the game, leaving ambitions like this for future productions. I'm actually surprised to see them limiting the promises they're making, and releasing these let-downs early. It shows some lessons learned from previous productions.
Nothing is saying they can't expand upon the Star Wars franchises and meet these demands in other productions, and I think supporters of these ideas would see better results pledging support for more games rather than jamming all this into a single game out the gate.