Spoilers
In case it’s not obvious, this is all my subjective interpretation - I am not sure what the intentions of the author were exactly.
Let’s start with the most “obvious” one, from chapter 3, which Rakka basically speaks out loud. Is マシュ一さん’s husband happy?
You mention that eventually the meaning of the morse code in the monitor is explained / deciphered, so this might not be a mystery eventually. But the idea is the basic question of at which point is it still ok to artificially extend a loved one’s life, which I personally feel is a extremely hard question to answer.
From humans’ perspective, I feel most of them would agree that this is too much and that he should be put out of their misery - but I feel this is just a rationalization of what a human would feel in that situation.
Is he suffering or in agony? Did he willingly accept to be connected to the machine? He clearly is conscious and can communicate. Perhaps he feels his extended lifetime is something incredible for his race, and being with his loved one is something he enjoys. After all, he’s from a different race. How does that race feel about death? What views do they have on the after life?
Even when they don’t reach such a dreadful state, humans grow old. They start becoming unable to do many things they could do, losing their ability to move by themselves, the ability to see, to hear… but they might still enjoy meeting their grand-grand kids and giving them sweets - while others feel they are a burden, or prisoners of an old body.
Can we really decide what’s best for マシュ一さん’s husband just from the information we have so far? Gorbit99 called it “horrifying”, and I called it “shocking”. Is it really? Does he agree? We don’t know. We just, biasedly, internalized the situation and thought it was terrible. Personally, I’d never want to live connected to machines - but this is just my bias. Maybe for him, it’s a blessing.
For chapter 2, Rojika mentions typhoons and says:
数の人類が死に至ったらしいよ
I thought the wording was strange. I am still unsure if 数の人類 a normal construction. Isn’t that “a lot of humanities” or “a lot of mankinds”, and not “a lot of humans”? Does this mean that humanity got wiped out several times, or something?
Actually I was confused at first and thought that when Rakka replies "人類ってばかなの” she was actually calling Rojika dumb for saying “a lot of humanities”, though eventually realized it was just “Is mankind stupid?”.
But that’s not the interesting question, the question is precisely what Rojika does next. He (she?) goes out, into the danger, and then explains he understand what’s basically the “thrill of danger”. Why do people enjoy doing this dangerous things, things that could easily kill them? It goes against natural survival instincts. Isn’t it very strange how such a thrill even exists? Rakka just takes the very rational point of view - it’s just dumb.
I feel these differences in point of view, implicitly make these kind of tacit questions. What is “beautiful”? Clearly Rakka and Rojika have different ideas about it, but their differences are so extreme. It’s somewhat different to the opinions of two humans would have - they would still have the common ground of being humans. Rojika and Rakka don’t seem to have that, even if they have other kind of things in common.
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This is what, the third time this happens in a row?
I initially thought along the same lines as 
(thank you everyone for mentioning it was wabun code so I could figure it out) It makes me feel so sad that on page 49 you can see the husband repeating it over and over on the panel.