I think you are either intentionally or unintentionally misinterpreting my wishes. As personal customization is going to be a big part of next generation RPG's, I think things like certain belief systems will come into play whether it be vegetarianism or feminism or whatever. I love the ME series as an action RPG, but you can clearly see the degree of sophistication increased from ME1 to ME3, so why not increase another degree or so from ME3 to ME4? And I am not one to say change or variance for the sake of it. I think enhanced customization could indeed make the immersive qualities of a game like ME that bit more of a great game.
Said 'sophistication' got more and more streamlined as the series went on, to a point where auto-dialogue was so prevalent that you really couldn't choose what your Shepard would say or feel at all. So the 'degree of sophistication increasing from ME1 to ME3' is bunk. As the series went on, there was more focus on the action, and less on the RPG.
As for belief systems, that would be addressed in dialogue, not in customization. At the absolute best, you're going to get one, maybe two statements about a topic and your character's stance on it, after which it will be dismissed never to be seen again.
I find that a lot of people find games to be more immersive when the story and plot is consistent with the universe and the story and character interactions take precedence, and where customization affects the story, not just existing for the sake of existing.
I get what you're saying. But customization comes in many flavors. It's not all good. I think a lot of people, including BioWare, will likely find your idea of customization to be pointless and insignificant. Sorry, but it doesn't do anything for the game.