It doesn't hurt to have other characters react to him, the potential problem I see here is in repeatedly showing the same reaction, which is likely. Confusion, a sense Hadden is a rude jerk, etc. The reaction of Lemarc is the obvious one to a Spock-like or Data-like character, which is what Hadden is. Showing the obvious response first is fine, but readers will likely get bored with it quickly.
I will point out there are a few other possible responses. Great offense, and a refusal to interact at all with somebody so rude and unfeeling. How will Hadden respond to that?
Brother Lemarc turned his outstretched hand palm up, looked at it, then looked at Hadden, furious. "You are not eager to take the hand of a holy man? By the word of the true God, you are possessed by demons. Leave this instant, I deny you access."
He looked to Zane. "Leave. You keep the company of demons."
Originally the handshake proved you carried no weapons. Perhaps that is still true in this culture, when Hadden does not shake hands, Brother Lemarc pulls a knife or gun and demands they leave.
Or just petulance.
Brother Lemarc realized Hadden wasn't going to shake his hand, and withdrew it. He folded his arms, his face grew impassive. "My presence is indeed required, and you shall not have it, until you learn to be civil. Return tomorrow, rude child, and I will judge your progress. Now, I rather fancy an apple, there is a nice orchard a few hours from here. Have a blessed day of learning, gentlemen."
With that Brother Lemarc, head held high, walked between Hadden and Zane, away from the Temple.
Of course even these could get tired after awhile. You don't want to show the same aspect of Hadden too often, usually if you show something twice, the reader expects you to show a character "learn their lesson" and overcome it. If Hadden is setback 3 or 4 times without ever learning his lesson, he looks dumb. If he's supposed to be dumb, okay, but if he is supposed to be smart, he probably realizes his mistake on the first setback, definitely by the second, and doesn't make it again, because he doesn't court setbacks.
So as a writer, you can't keep fiddling the same song over and over, it's like a concert where the band sings the same hit song twelve times and calls it a day.
You don't need to develop the walk-ons reacting to Hadden very much at all, stereotypes will do. A religious person, a prostitute, a businessman, a housewife, a taxi driver, a front-line soldier, a military general, a politician, a waitress, an artist. Or equivalent stations in your world.
Since Hadden is your POV, the reader expects him to have some super-goal to achieve that applies to his lifetime as a character (either a single novel, or throughout a series). Data (of Star Trek Next Gen) had the super-goal of becoming as human as real humans, which was accomplished in the end by intentionally sacrificing his life for his friends (which was not completely logical, but that was the point, Data acted emotionally in opposition to logic).
Emotion is frequently in opposition to logic, the proof is in any addiction: Logically alcoholics know alcohol is killing them, but emotionally they fail in resisting the feeling it gives them.
You can use the dichotomy of emotion vs. logic in scenes that educate and change Hadden. Obviously he has emotions, which I gather from his sigh: In general, the experimenters noted that sighs are associated with a negative mood—a sign of disappointment, defeat, frustration, boredom, and longing.
Sighs are also evident in sexual situations, to indicate longing or (the more positive) satisfaction. And it is true sighs can have a physiological reason (expanding the lungs to clear alveoli), but in writing we wouldn't call that a "sigh", we'd call it a deep breath, because 'sighing' generally connotes an emotion.
But the main reason I believe Hadden must have emotions is that we don't really act without them. No matter what we do, it traces back to an emotion. There is something we want to happen, or don't want to happen, and we act to affect the future. If we don't care about the future, and don't care what happens to us, if we live or die or suffer pain or joy, then we have no reason to act at all.
In Mathematics, we call the things that are self-evidently true without any proof "axioms." The only way you can prove any kind of relationship is to reduce it axioms, things that are self-evidently true and require no more proof.
In a sense, emotions are the axioms of life. Much of what we do is ultimately because we don't want to die. Why don't we? We just don't, we don't have to give a logical reason for that, and if we do, it is going to circle back to something else we want and cannot explain why we want it. Being less grim, I could say I want chocolate. Why? because to me it tastes good. Why? I don't care, it just does, give me chocolate!
You need to do a similar thing with Hadden, explore the axioms underlying his actions, what does he believe is self-evidently true? (Or if you find yourself reasoning in a circle, the set of things that explain each other and cannot be reduced any further).
This can vary from person to person (e.g. death is not everyone's #1 fear), but those things will also be his reason for being, and his super-goal will be consistent with them.
Then your incidents can be lessons for Hadden and create personal growth, making him more competent to pursue his super-goal and eventually achieve it. Or just better able to fit in.