Yes, choices have consequences, as we have already seen.
On the other hand, the major choices are not the ones that have consequences, they are there to define the personality of the MC. If we look closer, it's not a major choice that leads to the reaction of Bella who dumps us because of what we did with Katie. With Jade it's the same, the major choice only leads to a handjob under the table, then having sex with her and showing the video to the DIK (which lands her in the hands of her husband) these are not major choices.
I'm not going to be categorical, but I think the majority of major choices are without consequences. I don't remember all the major choices, but for the moment I see two that can have an impact: the restaurant, and cheating on the exam. The rest is just to define the personality of the MC.
As for the consequences of our actions, the further the story goes, the more it will start to happen. Do not expect huge stuff before the last episodes. In any case, DPC won't detonate a landmine that will impact a lot of major characters before the end of the game (eg Jade's sextape). On the other hand, DPC can make disappear a main character who is not linked to several plots (for example Jill from EP9 if we chose Bella).