It has it's strengths and weaknesses. I hated Picard getting talked to like that but it made perfect sense for the episode and it was portrayed excellently.Personally, while it took me a while to warm to DS9 I think this can be best reflected in the first episode. We have Picard meeting with Sisko and the emotional challenges that Sisko feels there. The feeling of things being "off" strikes me now as being very deliberate because Sisko is off. He is a man who is struggling with his sense of self, his new life aboard the station, and new role as the Emissary.
The way people talked to one another was also more casual than in TNG, so they had to do something to distinguish themselves from TNG.
Yes, because cultural expectations for Klingons are different from Ferengi. And Quark demonstrates that at the end, which Gowron acknowledges.
I agree that on a very surface level these elements feel very disparate but I think it is deliberate.
But this is why DS9 feels too much like it's own thing, for me. The Dominion War is supposed to be a huge deal in the world of Star Trek, but it almost feels like it's not canon to me. We don't even see Picard and crew get involved. How important can it be? It didn't even affect anything significantly in the movies. Now, I get the reasoning behind the scenes of why the producers did that, but it makes it feel more like this alternate reality series, to me. It's almost like DC Comics Earth 2 and Earth 2.
With that said, DS9 became a great series but it never felt like Star Trek to me. To be fair, neither did the TNG movies. GEN a little. The rest no.
But yeah, I agree that it's all deliberate. I don't like the tone change overall as it applies to the franchise or world of ST, but for the show, it made it fun. Quark is one of my favorite characters.