Question: When Roz pretends to be surprised about Niles and Maris separating, why does Frasier call her "Talulah"?
Answer: When Roz comes into the scene, she's complaining about Christmas shopping because she says that she never knows what to give the men in her life. Frasier replies, "Since when?", making a sly comment on Roz's sex life. Roz was often teased about having many men in her life (it was a different time back then). When Roz overacts in response to Niles' statement about getting back together with Maris, Frasier says, "That's enough, Tallulah." The reference is to Tallulah Bankhead, a stage and screen actress from the '30s and '40s who was also known for her sexual appetite.
Question: What happened to Julia? They spend time building up a character and then she dated Frasier and they broke up, and in the next episode there is no mention of her leaving the station - no one talked about her?
Chosen answer: TV shows frequently have short-term characters who never appear again. Maybe Julia got another job. Maybe Julia still works at KACL, even if she is never shown or mentioned.
Answer: She became victim to "Chuck Cunningham Syndrome." Which is described as: "when a character in a television mysteriously vanishes from the show. No write-off, no death, not even a passing explanation of what happened to the character."
It's annoying when they introduce the character build it up and then get rid of it with none of the characters mentioning it.
Question: Why does Roz have to screen people's calls before Frasier talks to them? We see in some episodes that he can answer calls directly if he chooses, so why doesn't he do it all the time?
Answer: Most, if not all, radio call-in shows like Frasier's have someone (usually a producer) who screens calls. Sometimes it's to maintain a queue, sometimes it's to filter out the boring/crazy/uninteresting ones (it is radio, after all...the problems have to have entertainment value). Mostly, though, it's so that Roz can get some basic information from them (i.e. their name and the general nature of their problem) before putting them on the air. It's basically quality control. Yes, Frasier can take calls directly, but like most radio hosts, he relies on his call screener to make a decision about which ones he addresses.
Question: Why does Maris keep Niles' last name after they divorce? She has more wealth and social connections than him, so she doesn't seem to have anything to gain.
Answer: One could say force of habit and all the years, but also because she is clingy and incapable, and may be hanging on to her whipping-boy/servant if only psychologically (furthermore, she gets into legal trouble and may wish to spread the stain and disgrace onto the Cranes out of vengeance).
I think she always wanted Niles to "come crawling back."
Question: Why did Niles stay with Maris for so long considering they hint she's horrid. That and why did they never show her?
Answer: Niles did love Maris, but he was very much a pushover who let Maris control his life. He accepted that because of Maris' money and connections, which gave him a very good life.
Answer: I forget exactly, but I believe it's along the lines that Niles enjoyed the social status that being married to her brought him, despite her flaws; it's somewhat akin to someone staying in a bad relationship because the sex is good. As for the second part of your question, the producers were planning to cast someone, but as the show wore on, the writers found they enjoyed writing Maris as an unseen character, and as the descriptions of her became more outlandish and contradictory, it was felt that finding the right actress for the part would next to impossible.
Answer: The other answers accurately explain Niles and Maris' relationship. As to her never being seen, Maris is a version of Norm's wife Vera in "Cheers." Vera remained unseen throughout the entire series, but was often talked about and incorporated into various episodes. It was left to viewers' imagination regarding what she looked like and guessing if she'd ever appear. Vera sort of appeared in one Cheers episode when she was hit by a pie that entirely covered her face. Her voice was also occasionally heard. This same plot device was used in "Frasier."
Answer: The cheating occurred during "Cheers." Not much was discussed about the reason, but she cheated on him with a colleague of hers, Dr. Pascal (whom she also went to live with in an underground eco-pod). Working closely with someone, especially if the two have similar likes, ideology, etc, can result in romantic feelings being developed. With the burden of marriage and a child, she may have given into her urges. She does obviously feel bad because she asks Frasier to forgive her and take her back. There was also a running gag on "Cheers" that Lilith had a strong libido that she had to work hard to suppress, which may have been a factor if true.
Frasier Gotta Have It - S5-E19
Question: What does Martin mean when he says Caitlin is a flake?
Question: Did they ever hint on this show or Cheers that Lilith was Jewish, before this episode?
Answer: Yes they did hint at it, but her religion was down played because they didn't want that to define her character. But besides the "Cheers" episode mentioned, s10e06 of "Frasier", "Star Mitzvah", is about their son Fredrick's bar mitzvah. Typically under Jewish law, a child is considered Jewish if his or her mother is Jewish (and we know Frasier isn't Jewish). It should also be noted that Lilith is a figure in Jewish mythology and considered to be the first wife of Adam.
Answer: Yes. The 'Cheers' episode 'For Real Men Only,' deals with infant Frederick's bris (ritual circumcision).
Question: There is a laugh track sound about the mention of Julia's book, "Day-Trade Your Way Out of Debt." I've heard of day-trading but don't really understand it. What is funny about the book title?
Answer: Day trading is a risky form of speculation where one can lose a lot of money, and is not a good plan to get out of debt.
Answer: It's just one of Frasier's little arcane witticisms. Roz is acting over-the-top surprised (hands on her heart, wide-mouthed gasp, etc.), the way theatre actors and actresses would back in the early 20th century. Tallulah Bankhead was a successful American stage actress of that era, so Frasier is comparing Roz to her after seeing her "performance." He (or, more accurately, whoever wrote the episode) probably chose to reference Bankhead out of all possible actresses because it's an unusual name, unlikely to be confused with some other, non-theatre Tallulah.