Picard himself can hear French when he speaks it. Other people in-universe who understand French can understand it - we the audience don't hear it, as we get the benefit of the UT. You ever think that maybe, being a zillion lightyears from home, he'd like a little reminder of home?
Like I said, most human beings today are bilingual, and humans on Earth in the 24th century Federation most likely learn English from childhood along with whatever their local language is. English would be just as much a "reminder of home" for Picard as French.
And like I said, no machine translation can ever be perfect. He'd be a fool to rely on translators to convey his orders to his crew -- especially if some strange cosmic phenomenon or alien attack blew out the translator circuits.
Of course he speaks the same language as the rest of his crew. Anything else would be criminally negligent and stupid as hell.
And let me put it this way - have you ever met a Frenchman who spoke English with a perfect - and in this case regional - accent?
Like I said, I'm aware of multiple actors who come from Latin America, who speak Spanish fluently with a Latino accent, but who also speak fluent American English with little or no trace of accent. I'm also aware of plenty of British and Australian actors who have played Americans on American shows and rarely if ever show any trace of their native accents -- Hugh Laurie, Anna Torv, Jamie Bamber, Anthony La Paglia, Poppy Montgomery, etc.
And what makes Picard's English accent any more "regional" than Riker's American accent? There was a time, much closer to us than
Star Trek is, when British influence and British accents spread across nearly the entire planet. And 24th-century Earth is much more culturally unified and homogeneous than our Earth. English is clearly its universal language, and speakers may be more or less evenly divided between those who use American pronunciation and those who use British. Indeed, if historical precedent and geography are anything to go on, the latter could well be more common.
Sure, no doubt that'll change over time, but the bottom line is either way, we're just trying to rationalise something which isn't explained onscreen! Unless and until someone turns around and says to Picard onscreen 'Wow, Jean-Luc, your accent is brilliant for a Frenchman!', we won't know.
But the point is that it doesn't need an extravagant explanation because it's not unprecedented in real life. As Carl Sagan said, extraordinary claims require extraordinary evidence. If there's a perfectly commonplace explanation for something, as there is in this case, then there's no logic in claiming that a complicated, far-out explanation is equally plausible. It isn't, not at all.
So I do think that Picard, proud Frenchman as we know him to be, would also be happy to speak his own language when he likes. I never said that he didn't speak English (he's a multicultural, broad-minded sort of guy, of course he'd be multi-lingual), just that he speaks French.
Of course he can speak both. I've already pointed out repeatedly that most human beings are bilingual, so that should be axiomatic. My point is that there's no mystery behind his ability to speak English with correct pronunciation. If he learned and used
both English and French from childhood onward, which is overwhelmingly probable, then it makes perfect sense that he could speak both languages without an accent. As I said, he may speak French all the time when he's with his family or with Francophone friends, but when he does speak English, as he most likely would when serving as a starship captain, it shouldn't be shocking that he can pronounce it correctly.
Of course being multi-lingual is good (I speak English, French, Irish and a little Spanish) but the flip of the coin is that as English becomes more prevalent, minority languages become more endangered.
In "Code of Honor," Data did call French an "obscure language." And that's all the more reason why it shouldn't be surprising that Picard can speak and pronounce English fluently.
Finally, I really don't know where you're going with the whole probes point. I mean, TUC showed how dependent on the translator the 23rd century Starfleet was, for one thing.
When dealing with
alien languages that are poorly understood, yes. Like I said, it makes sense that the translator, imperfect as it is, would be used in circumstances where there's no alternative, like in dealings with aliens whose languages are unknown or little-known. (And TUC is a crappy example because it was completely idiotic to postulate that nobody on the crew spoke Klingonese. They tossed credibility out the window for a stupid gag.) But that's completely different from using it for translation between two common and well-understood human languages. That's like the difference between using a car to drive across country and using it to drive half a block, or the difference between using a calculator for solving complex quadratic equations and using a calculator to add 3 + 7. The former is a necessary use of technology to do something you can't do yourself, the latter is just a lazy and pathetic dependence on technology to do something you're perfectly capable of doing yourself.