Well, I think we agree on some things and disagree on others. I also think traits giving stat bonuses is a bit dubious. Neat in theory, but in practice, it tends to encourage people to roleplay in a certain way to gain certain bonuses. And also, some bonuses are way better than others. I don't think it's a huge issue, but I hope they affect dialogs and stuff more so if there's stat bonuses, that won't really be the biggest consideration. I mean, the player's moral concerns should be the biggest consideration anyway, but some people need a bigger push.
I really don't think the origins are going to be gimmicks. They're going to have huge impacts on the game. Maybe not every single area will have unique things for each origin, but they very well could. If the demo was any indication of how origins and race will affect quest possibilities and character reactions throughout the game, we're in for a highly reactive world. I'm sure Larian has more money to spend on D:OS2 than D:OS1, not event counting the kickstarter, since D:OS1 was so successful.
Another way to deal with your concern of combat being balanced with or without combat talents in mind is to make a bunch of entirely optional, very difficult fights. So someone with a shitty build for combat might have a really hard time winning these fights, but they won't need to win these fights to get through the game. The arena will be a good place to do this, as well as various sidequests, maybe somehow marked as "challenge quests" or something with a disclaimer to explain that these are quests with hard as hell fights only for the most hardcore. Probably people will still complain about that, but people will complain no matter what.
