Just read the post above “My shocking story” to see what can happen. It seems despite everything most lawyers are still assisting the developers by allowing their clients to complete without giving them apropriate advice (I’m not getting at the lawyers on here, I know you don’t). Think its time the lawyers colegios held a few training days to update them on what is happening (and teach them about ethics).
regarding the size of the apartment, there are some previous posts on this and you can be awarded compensation. Do you have an independent lawyer or were they recommended by the developer/agent?