A Midwinter Night's Dream - S1-E17
Plot hole: Niles makes up Frasier's couch to sleep in and when he lies down he lets out a yelp - and pulls a plastic pirate's hook from behind the cushions. Earlier Niles had appeared wearing a pirate's costume but at no point did he have a hook, nor did he go near the couch. His overcoat had been on the floor the whole time so it couldn't have come from there. It would have been difficult for it to get behind the cushions unless deliberately shoved there, which we never saw and makes no sense anyway.
A Midwinter Night's Dream - S1-E17
Plot hole: Niles phones Frasier to tell him Daphne is staying at his place because of the storm. Frasier's phone is in its usual place on the room divider/bookcase behind Marty's chair. After Frasier and Marty leave to rescue Daphne, Niles phones again and Eddie is standing up on a chair staring at the phone. Only problem is, the phone is over on Frasier's desk, where there normally is no phone. If he did have a phone there, it is only a few feet from the other one, which makes no sense.
Plot hole: Once the gang have arrived in Canada, Daphne is scared stiff of getting caught outside the USA. Marty explains they will just "smuggle" her back and Frasier and Niles are outraged at such deception. But to get into Canada, all of them would have had to declare their residence, birthplace, and reason for coming in. To get Daphne in in the first place, they must have lied. She would have had to show her passport as an alien. The Americans would have been allowed in without their passports, per diplomatic agreements. So the outrage of the boys makes no sense.
The Botched Language of Cranes - S2-E6
Plot hole: Several times throughout the show, it's bought up that there is a seven second delay on Frasier's show at KACL, which, among other things, would allow Roz to "dump" the last seven seconds of what's been said and prevent it from being broadcast. When Roz notices that Frasier is still on the air during his rant, it takes her about nine seconds to get back to her console, so she should have been able dump the last seven seconds of his rant, leaving only the first few words of Frasier's rant (likely no more than "Good Grief, have you...") going to air, which would be much less awkward compared to his entire rant. (00:09:20 - 00:09:50)
Plot hole: In this show Daphne's former fiance, Clive, shows up. They had been engaged for several years in England. However, in Series 1, episode 11 (Death Becomes Him), Daphne talks about never having had a serious boyfriend, and goes into some detail about how people tried to set her up with eligible men. As Daphne is open about everything else, there seems to be no logical reason for her to not mention she'd been engaged.
Plot hole: During the scene when Frasier is in Cassandra's hotel room, he phones Roz and puts his phone back in his jacket pocket. He hangs his jacket on the back of the chair and eventually gets into bed with Cassandra, who soon falls asleep. He talks to her but she doesn't answer. We then hear him phoning Roz - but there was no time for him to get out of bed and get the phone - and no sounds of him doing this.
Plot hole: When Frasier is trying to get to the bottom of Niles' problem viewing Daphne in a real way, we see them both against past scenes in the show; Frasier watches and comments on some of them as he talks but because he is actually only discussing these events with Niles, he shouldn't be able to see a visual of anything such as the dress Daphne is wearing during the dance scene.
Answer: In the last episode, they explained that Tossed Salad and Scrambled Eggs is a metaphor for the mixed-up people to whom Frasier dispenses his radio psychiatric advice.