I'll have to say no thanks to auto-guilt. That sounds more annoying than interesting. I didn't like it when they tried it with Shepard, and I don't want it here.
They butchered Shepard with the auto-emotions in ME3, but that's an entirely different thing. Having haunted dreams about that little kid and being forced into being an emotional wreck was moronic. Keeping the dog tag of the person whose death you caused is a very different thing. Hell, they could even let you determine what exactly you did to cause Ryder's death(your mistake caused him to die saving you, you allowed him to die to save yourself, or you actively murdered him to advance your career/station in the expedition) and how guilty you feel about it. Throw in Ryder's sibling looking into what happened/eventually finding out and you you've got same tasty drama and character development in a series that is otherwise very straightforward and pedestrian.
Imagine a subplot wherein you murdered Ryder, his sister finds out but you find out that she knows before she gets a chance to tell anyone and you have to choose whether or not to murder her to keep your secret, confess to the crime and potentially end your campaign then and there, or take your chances trying to convince everyone that you're innocent.
Or a scenario wherein you accidentally caused Ryder's death, the sister finds out and holds it over your head to get what she wants(maybe she's xenophobic and wants you to assist in cutting other races out of leadership roles) and the longer you help her the harder it becomes for you to redeem yourself in everyone's eyes, but if you don't help her at all you may never get the chance to redeem yourself, depending on how much influence you have in the Ark.
It adds a new dimension to story and would do a lot to set Mass Effect apart from other games.