When there is a sensation present, isn’t it automatically known without any thought saying that ‘a sensation is there’?
Wow. This is really interesting. This is absolutely true. The thought of "there is the sensation" just happened to arise before. I wouldn't have considered the thought as necessary.
Yet more insight came when I considered your question. Initially, I felt a challenge arise to the notion of sensations "automatically" being known. A thought arose that only the sensations that are KNOWN are "automatically" known. This challenged the assumption suggesting that there are other sensations happening that are not known.
The experience of paying attention to sensations has the character of randomness. As different areas of the body and experience become more prominent moment by moment. Yet, when a particular sensation is being noticed, it's merely an assumption to think that there are other sensations occurring simultaneously that are not being noticed. So, yes, everything is just automatic including the thought "well, that's happening."
Does a thought is needed to know that there are sensations present?
No. No thought is needed to connect with the sensations.
Just because there is a judgemental thought, does this mean that there is a delusion?
No. Delusion would come once the thought is believed to be coming from a "me" that is somehow separate from that which is being judged.
Does the judging thought should stop appearing in order to be clarity?
No. Clarity can happen in the midst of judgemental thoughts when they are seen as the figments of imagination that they are.
Or is it enough to see the judgemental thought for what it is, just a thought appearing?
Yes, it is enough to see it for what it is, just simply appearing. It's enough because it's all that is actually true. There is nothing else happening. In this way a "judgemental" thought is just the same as a "non-judgemental" thought. There's no better or worse. Thoughts are thoughts...
I had an interesting experience yesterday that I thought I'd share with you. I have two daughters, one of whom is 8 years old and the other is 2 years old. The oldest is understandably having a hard time adjusting to so much attention being given to her younger sister. Our little Lacie (2 year old) also has special needs, so she likely even gets more attention than your average 2 year old. Anyhow, May (8 year old) got into a bit of trouble yesterday for pushing her sister over. This all happened when Mom and I were out of the room. So, I had to do a bit of digging to figure out what had actually happened. When May was explaining the situation to me through tears she insisted that she "didn't know why she did it" and she asked what I do when I realize I'm "not in control of my body"... I marveled at her clarity and insight.
My best parental move was to tell her that she needed to "believe" that she was in control of her body even when she feels like she's not. Also, that admitting our wrong doings and experiencing subsequent consequences are important to curb behaviors so that they don't go unchecked and turn into worse and worse actions. Just then I realized my assisting her in building the illusion so that she can just tear it down later... Our whole life is a Santa Claus story. I always prided myself on not telling my kids to believe in Santa because I didn't want to be guilty of being dishonest with them. Yet, the illusion of Santa is really not all that different from the illusion that we paint through behavior modification and insisting to our children that they have autonomy.