I think maybe you're onto something.
I would compare the white noise thing to letting someone know that they are stepping on my foot. They may not have intended to, and I'm assuming it wasn't intentional. As soon as they get off of my foot, then I can go and get them those cookies they wanted. The problem is over. It's only when they remain on my foot and I've stated it different ways that I start to wonder what is going on. In here, I feel like I am trying to be helpful by stating what the problem is, but it is seen as an intentional attempt to attribute bad motives to the other person. This confuses me, but there must be some kind of link that I am not seeing.
I guess I when I look at cause and effect, I tend to factor in intentions of the person or why they are acting as they are. Often I think that no one intended real harm, even though nevertheless harm was done. Figuring out the why of it, helps me to either reframe what happens from a new perspective, or else it allows me to plan for how we could avoid the unfortunate outcome for next time. A lack of remorse is not making efforts to plan for a different outcome next time by adjusting one`s approach.
If, (and I don't know about this, so I'm just throwing it out there), you instead are focussed on how anyone in the chain of responsibility made other people feel in the process, then perhaps validating and experiencing the feelings that transpired rather than avoiding the outcome next time is the focus. In this case, a lack of remorse would be not taking responsibility for creating certain feelings.
Maybe us talking about creating white noise implies a sense of blame for uncomfortable feelings created, when we are just saying, "When you state things in this way, it slows down my processing ability and makes me unsure of what you are looking for".
I`m realizing that Ne tends to talk more in specific situations rather than overall patterns. Therefore, what seems to me like a deeper criticism brought up in a specific situation, is only meant at face value. Perhaps there is an opposite equivalent of that regarding Fi or Si where a deeper criticism is implied even though we only mean it to be taken in a specific situation and at face value. I`m kind of thinking aloud here, so I haven`t really had time to test that out.
That doesn't really explain the "something about this does not make sense" equalling a doubt of sincerity though. Although maybe it was because the people in her INFJ experience did not taking responsibility for the feelings they created, it indicated a lack of awareness or remorse. Maybe INFJ and INFP focus on different aspects of the problem and so remorse looks slightly different to each of them?
I don't know. Maybe I'm way out in left field.