I was going nuts for ages trying to figure out how you got there until I realized it was literally in the picture.
I guess I’m a dunce when it comes to shounen, but after struggling with decorative cover fonts I found out the series is Kenichi: The Mightiest Disciple. Skimming through the summary for that arc did not help a bit. Maybe I’ll go back to the graded readers for a bit… >.>
I don’t know the story or notice the picture but I recognize こいつ・そいつ・あいつ is much like こやつ・そ奴・あやつ. Which has a dudes/bastard or this/that/that over there guy(s). He if he wants revenge strongly, I suspect they aren’t friendly 
This one is not very easy. What is a MO? (Magneto-optical disk?)
What? Oh yes, as long as there is this MO
毎日日本語を勉強するかぎり、進みます。
July 10th Translation
Notes: The key indicators for what this sentence is trying to convey lay in the ある and the 。。。One of our main notes for かぎり is ‘A限り、B. means that as long as A continues, B will not change’. Here, A is ある and 。。。 is B. The way we can interpret this is that the mere existence of the disk is preventing something, or allowing something. In this case, the character then goes on to destroy the disk, showing that the 。。。 actually meant ‘As long as this disk exists… it’s getting in the way of my plans!’.
What is a MO?
In Japanese: https://e-words.jp/w/MO.html
In English: https://en.wikipedia.org/wiki/Magneto-optical_drive
About that / that means, these guys made great progress [and…]
Not quite sure how to interpret それは here without context 
Those Gs are evolving too much…
This series was a little… tough… 
This cockroach has evolved/progressed too much Complete shot in the dark here, probably not right. Kana threw me off until I looked it up and remembered I saw it in some holo video ages ago
Didn’t understand what’s going on your picture.
This guy is ゴキブリ？🪳 He doesn’t look so bad 
The explanation makes sense, かぎり is a powerhouse grammar point. I thought it was extent of capacity given MO instead of existence, oh well.
Lit: That is an over-evolved cockroach
I really don’t know or why コイツら is in sub-text, if we are saying cockroach in Tony Montana way…I don’t know the manga to know what is going on here If so it’s like “They are piece of garbage” given the de-evolved/over-evolved…whatever over-evolved means here w/ コイツら.
食べすぎたから、お腹が痛かった。
The basic premise of this series is that humans sent genetically modified cockroaches to Mars as part of a terraforming project. The cockroaches had evolved to a point of taking on a humanoid form, being able to use tools, acquired external DNA, ect. Then it quickly turned into everyone’s favorite shounen animal fact of the week superpower battle between the two races. It was… eh… … there was a lot of not so great discussion regarding various elements including the meme tier censorship of the anime.
Now that you’ve pointed it out, I don’t think I’ve ever noticed a different word written out like that. Is that common?
Regarding the コイツら, what about this point? ~ら It says it applies to pronouns, which should include こいつ. Something along the lines of “This thing and it’s buddies…” or just “They…”? I kind of made that assumption because the picture had all the roaches in the background, but this would solidify it.
The ら for groups of things that you linked is the same as the one in this picture. It is very… very common for there to be furigana showing the ‘true thoughts’ of the speaker, rather than what they are actually saying. So something like 了解（しまった）！ would actually be pretty common to see.
It can literally be any combination of words, and just means it is what the speaker is thinking vs what they actually said. So here, he literally said ‘cockroaches’, but was thinking ‘these fu**ers’ because they are at war with them.
This is a coackroach that evolved too much and…
日本料理はめちゃ美味しいので食べすぎずにはいられないね。
July 11th Translation
Note: It looks like a few of you noticed the difference between the furigana of one word, and what was being said. This is very common in all types of literature, so requires a strong kanji knowledge at times to realize that the furigana is not actually for the kanji, but actually just a joke or something similar. The furigana portion will always represent the person’s true thoughts, or will just be a dumbed down version of something ridiculously complex the speaker said. When it is ‘dumbed down’, the nuance is usually that the speaker is being pompous, and any normal person would have said an easier word.
Ah! Kaguya-san stayed too, isn’t it?
Ah! Kaguya-san also stayed yeah?
Since we are presented with the colloquial version here, it may worth mentioning it in the entry that we can use てた
Oh! Seems Kaguya also remained, right?
寝ていたけど、今聞いています。
Ah. Kaguya was remaining too, wasn’t she?
仕事が終わったあとで私はたくさんのことをしていたので、遅く翻訳を書いてしまいました。
July 12th Translation
Notes: While a fair few of you are probably accustomed to the ～てた form of ～ていた that drops the い, something which may also be worth paying attention to is formal speech. A common mistake people make is using the shortened forms in polite sentences. While it might seem like a fairly innocent change to shorten ていた to てた, it actually reduces the formality quite a lot! So you will never usually hear short forms used with any type of keigo.
