Wow, plenty of stupid on display in "Sacrifice of Angels" and I'm not even halfway through it.
Not sure where Armin got the idea that "Ferengi don't kill", but he seems to have made up that concept entirely in his own head. It's not remotely established in canon anywhere.
Sure, there are a few references to Ferengi preferring negotiation over war, but that's about it. There are plenty of times, mostly in TNG, to be fair, where Ferengi are perfectly happy to use deadly force or who are explicitly trying to kill people. Hell, in "Peak Performance," a Ferengi Daimon, played by Armin, is just about to obliterate the Enterprise capriciously for no reason whatsoever except for funsies.
And, on the subject of Armin, he also brings up (again!) his confusion over why Dax pilots the Defiant. As if a Starfleet officer couldn't possibly have more than one skill. The others always bring up her past host's lives, but that is beside the point. Robbie is often mock-annoyed at the fact that seemingly anyone can pilot a ship when that was character's sole area of expertise.
But it's perfectly acceptable that Dax would have more than adequate piloting skills even without having past lives. Hell, Geordi on TNG was a pilot and an engineer. And because TNG made that switch, they often found themselves in the position of having to have a non-speaking extra on the bridge instead of a regular character. DS9 wanted to avoid that, so they slotted Dax into the piloting position, which is perfectly acceptable canonically and also makes good use of the show's cast. (Armin routinely forgets that he's watching a TV show which occasionally has to slightly bend "real world logic" in order to do things, like, say actually feature the show's core cast. God forbid.)
Far more egregious, which they reasonably point out, is Bashir's presence on the bridge, or later Ezri's role on the bridge. I'm sure we'll hear about that when the time comes.
Armin also stupidly says the Founder should put a guard on Odo. Are they even paying attention? The Founders would never, ever do that. A few episodes ago, the Founder said Odo was literally more important than the entire Alpha Quadrant. The Founders consider solids to be lesser life forms, they would never insult one of their own by putting him under guard.
And finally Garrett pipes in with the idiot comment of the week, saying it's a "plot hole" that Rom can tell a Bajoran phaser from a Federation phaser. Hell, I can tell the difference between the two! Does he honestly not think the sound effects department is actually doing their jobs? Do they really think all phasers sound exactly alike? They don't, genius, and never have.
It reminded me of the fact that they were baffled for years over the station's computer voice and wrongly assumed it was Majel Barrett despite fact that the voices sounded entirely different and that DS9 is a Cardassian station, it wouldn't have the voice of Starfleet computers in it.
Oy vey....these people....