Ok. And I will try to be as clear about this as possible.
The only proof you have is the Finley scene, the ridiculous claim that anything Maestro says must be wrong, and the even more ridiculous claim that the computer's inability to translate alien speech means that the computer can translate alien speech. Those latter two claims are so utterly pathetic that they don't just fail to prove your point, they actually make it impossible to take you seriously. At all.
But, let's be fair, and look at the Finley scene, which is your only valid evidence. Here is what the bug has to say:
"We have captured another of the non-aligned and are transporting it to the Centrax on Dula Seven."
This is clearly not enough to prove that the bug talk is translated. If you had more evidence, this could be used in support. By itself, however, it simply doesn't stand. One can just as plausibly assume that the bugs spoke English for a reason - remember that bit Blair said about the bugs letting us find him? This message may have been in English for a reason - it may simply mean this: "we think you can decryot our messages by now, but we want confirmation. Oh, and we have Blair. We're holding him at Dula Seven. Feel free to drop by to pick him up, eh boys?"
But, but, but... doesn't it make more sense to assume that the bugs really were translated in the Finley scene? Well, uh, no. There are two reasons for this:
1. Maestro says they learned our language. Maestro, contrary to popular belief, is no fool. He graduated from an exclusive prep-school. He went to the academy on a whim - and graduated with good results in spite of a record number of disciplinary infractions. He must have been good at more than just flying to achieve that. The fact that Paladin, in his infinite wisdom, deemed it worthwhile to get Maestro assigned to the Midway together with Casey confirms this. The fact that Paladin thought Maestro should keep an eye on Casey in the first place, confirms this. Want more evidence? When the bugs first try talking to us, who's got the presence of mind to open up a voice-link to Finley? Not Casey. Not Stiletto. Not Dallas. Not Maniac or any of the vets. That's right - it's Maestro.
Want more evidence still? Maestro's kill score in WCP is usually nothing special. But he gets assigned to the Cerberus. Two cream-of-the-crop assignments in a row? And indeed, an Intel assignment? Guess what, Confed High Command didn't send him there for comic relief. In Secret Ops, who gets dispatched on assignments that require more than just flying skills? No, no, it's not Stiletto. Not Casey or Amazon, or Spyder. It's Maestro and Zero. And when they find the Albergetti wreckage, again Maestro shows initiative by landing to provide Zero support. They save two lives, and manage to do it without even getting contaminated.
More evidence? Fine. Yes, Maestro is wrong about the significance of the two suns in Proxima, but at that point in time, he, oddly enough, is the only one of our six young heroes to actually try to come up with a logical explanations. And guess what? When we find out about the wormhole, Confed decides to capture it rather than destroy it. Curiously enough, Maestro is the only one of the Cerberus pilots to think of that before their mission is explained to them.
So Maestro, in spite of his sometimes childish behaviour, clearly knows what he's doing. He may not be a big fan of discipline, but he is most definitely considered a valuable pilot and officer. I undoubtedly over-embellished his abilities in the text above, but don't bother pointing that out - even if half of what I say is pure bullshit (and it isn't), the other half is enough. A quarter or even less is enough - there's simply no reason to doubt Maestro's competence.
Conclusion? When Maestro claims that the bugs learned our language, his claim is much, much, much, much, much, much, much, much, much more credible than anything you've come up with so far.
2. Hypothetical situation. I tell you a number. You know it's just one number in a vast pattern, but you don't even know how many other numbers there are. Can you tell me what the pattern is? No. Is there, or will there ever be a computer sophisticated enough to work the pattern out? No - there is not enough data. This number is a bug word, and the pattern is their language. But the bugs spoke more than one word, right? Sure, they spoke at least ten-thirty different phrases. Probably about a hundred, maybe two hundred different words. Ok, so you have 100-200 different numbers now. You don't know their positions in the pattern, and you don't know how many other numbers there are in the pattern. Can you tell me what the pattern is? Umm, still no. Will there ever be a computer capable of telling what the pattern is? Nope, still not enough data. There's no point of reference. You can guess a thousand times, and each time, your guess might seem perfectly logical - and each time, you wouldn't even know if it was right. You see, that's why we still can't read Etruscan, even though we have many samples of their writing (and even though they use a known alphabet). We can guess from the context of the writing what they probably wrote about, but we just don't know what words they used. That's also why the Rosetta stone was so important - without it, Egyptian hieroglyphics were doomed to remain gibberish forever.
Conclusions? When that computer says "unable to translate", it's not just being cute. It really can't translate their speech. The universal translator, as seen on Star Trek, is a fictional plot device that will never exist. There's no reason to assume that its existence in the Star Trek universe makes it possible for such a device to exist in the Wing Commander universe.
Carrying on that line of reasoning, what's more logical? A Confed computer performing a miracle that would surely put the fear of God into not just the Nephilem, but every other species in the universe... or maybe, just maybe it's more logical that the Nephilem, who have access to hundreds or thousands of prisoners, who are apparently able to extract anything out of a man (whether through mind-reading of some kind or sheer torture-based persuasion, it doesn't matter), would learn our language?
All things considered, you have no proof. We have a position very strongly supported by both direct (Maestro's claim) and conjectural (the implausibility of your amazing translator) evidence. You don't have a leg to stand on in this argument.
There. You wanted me to explain why I think you're talking nonsense? Fine, I've done it. I've said absolutely everything there is to say here. And if that doesn't persuade you, for crying out loud, at least have the decency to stop bringing up the same worthless "evidence". Maybe one day a new WC product will prove that you were right all along - but until then, all the signs indicate that you are completely wrong.