Pg. 8, 4th Panel
That’s similar to the translation I get, though you are adding a “see” that I wouldn’t, and using the なる as a verb “to become,” which I interpreted differently. I translated it as, “This is (implied: the way to find the cat), you know. (This comes from the これはな that precedes what you typed out). Getting the cat’s point of view by doing this.”
なる = to get, as well as to become, so I took that meaning instead, and with the こと suffix, I think it’s a nominalizer, so it turns the なる into a noun.
Pg. 10, 3rd Panel
Let’s break this one down:
一度 = once; one time
して = て form of the verb する, to do. It’s in て form, because it’s conjunctive to the following piece:
みたかった = compound word みる, to experience + たい, which is an auxiliary adjective that means “want to”, conjugated into “past” form.
の = explanatory particle
これ = this, added after the sentence to clarify the subject which would have been unclear.
It’s a lot, but altogether comes out to:
“I’ve wanted to try doing this once.”
Pg. 10, 4th Panel
I translated more along the lines of, “In this way, you are completely warped!”
It is conjugated that way because it’s basically a compound word: 歪んで (conjugated to て form for conjunctive) + じゃう + ん, じゃう is a form of ちゃう, which is to do completely, and の, contracted to ん, which I think is the explanatory の rearing its head again, though I could be mistaken, and am open to correction.
Sacchan is essentially telling Kotoha that her personality is warped/twisted.
Pg. 10, 5th Panel
Close. The first sentence is actually a command: “Don’t say things like games are a bad influence.”
Pg. 10, 6th Panel
I actually interpreted that more along the lines of “That’s even worse, isn’t it?!”
余計 = all the more, even more
だめ = not good
じゃん = shortened version of じゃない, meaning “isn’t it?” in this context
“That’s even more not good, isn’t it?!”
English would turn “more not good” into “worse”
Sacchan says it in response to Kotoha saying she has always been like this.
Pg. 12, 2nd Panel
First question: I would actually say “Oh, Colors-chan, how is it going?”
It’s a different spelling of どう, or “how”
Second question: Yep, that’s the same way I read it, roughly.
Pg. 12, 3rd Panel
I would actually say the sentence translates to, “Weren’t (these glasses) stolen by a panda-like cat?”
盗まれる = to be stolen, which I think is what you are misreading as “to be caught”… That would be 捕まる
It’s in the passive form of the verb because the glasses are being acted on by the cat. It’s negative because of the way the question is framed. We often do the same thing in English: “Isn’t that true?” etc, etc. Hopefully that makes sense, I’m simplifying it down quite a bit.
As for the other question on this panel, you have the interpretation right, other than the wrong translation of 盗まれる coming back to haunt you:
“That’s right! (The glasses were stolen by) a seriously annoying cat!”
Regarding the particle, I haven’t read よつばと to say if it’s the same one, but I would guess that’s the case. In any case, it is a masculine sentence ender similar to よ, but much, much less polite.
Pg. 13, 2nd Panel
This is another one that might be easier to just break down:
それで = Because of that
この子も = This kitten (technically child, but they are referring to the cat, so), with the も particle, meaning also
アジトを = Secret hideout, with the を particle marking it as the direct object of the verb
住み処に = habitat, dwelling residence with the に location particle
してるん = する, in て form to indicate an ongoing action, and the の particle, contracted to ん. As before, I believe this is an explanatory の, but am open to correction on that
じゃないか = isn’t it?
って = casual form of quotation particle, essentially a verbal quotation mark
琴葉が = clarification of who said the quote. She is referring to herself by name, which by my understanding is fairly common among young children
Again, it’s a lot, but taken altogether, I get an interpretation along the lines of:
“Because of that (referring to the previous speech bubble), ‘This kitten is using our hideout as its home too, isn’t it?!’, Kotoha said.”
As for the second part of the question, that’s fairly close. I don’t think there’s any indication of “waiting for the right time” in her sentence though. I read it simply as, “And then, just like that, we were successfully ambushing (the kitten).”
Pg. 12, 4th Panel
I would actually say, “If you entrust me with the cat, it will no longer be able to stay in this town. By the looks of it, it’s grown attached to you. Train it not to misbehave.”
The clue for the first part being “If you entrust me with,” is the に particle. That indicates the action is going to 俺, as opposed to 俺 being the one doing the action.
Hopefully I managed to answer everything in there. If not, or if something I said doesn’t make sense, let me know!
@basoomie
こと and これはな
こと is a hard thing to pin down, because it’s so vague, and has so many uses. I’m not 100% confident in how I read it, but for me, the こと is the one that’s supposed to nominalize the なる, changing it into a noun. It’s a subtle difference, but when it has the こと, I would read the sentence as I translated it above.
Without the こと, I would read it more like, “Doing this, I get a cat’s point of view,” which in context would still probably work, but she’s not trying to tell them that she gets a cat’s point of view by doing what she is doing, I don’t think. I think she is trying to say that getting a cat’s point of view is the way to find the cat. I could be off-base, but that’s my interpretation.
To that end, I did read the な in これはな as a sentence-ending particle, yes, that basically means, “You know.” It’s a softer assertive than よ, but still an assertive, emphasizing sentence ender. I could be wrong on this, though, and am open to correction, as always.
Edit: I changed my answer format because it was an awful wall of text… Now it’s several walls of text hidden in sub-blocks, instead. 
結衣
さっちゃん
琴葉
斎藤
おやじ
oops nevermind