Oh these are good questions.
Weirdness is hard to measure objectively but Tarinda's heard of somebody who's a snake with wings! They had to get it done in stages so they'd be able to move around, remapping to a new body plan takes some practice.
TARINDA'S own personal hobby is combat dance. She thinks that one's coolest. But her girlfriend likes trail riding on her pony! It seems like it would be hard to go as far as some of those trails go in this bubble. Also she hasn't seen any horses.
Some Martians are monogamous. It's a personal decision.
Tarinda would most miss her girlfriend and friends, but assuming those don't count, definitely the robot servants. She can't think of anything she'd be particularly relieved about, though she guesses she won't have to ever tell her friend that she's gotten kind of tired of all the Greek-themed set pieces and would rather circle back to the Egypt stuff they were thinking about doing together?
There are astrophysicists.
Tarinda's not sure anyone's going to ask about non-Mars places! There are plenty of those! People live on asteroids and space stations and moons and Earth and Titan and stuff! Mars is the second largest population concentration, but there's more options than just Martian ones.
Birds on Mars are not all that smart so Tarinda is not aware of any special bird-smartness-favoring circumstances there but perhaps if it's important to them for some reason that has not historically come up among the Sing-influenced population it'll be doable?
She met a Sugardream Friend once who had an entire tirade about how Sing, uh, murdered and ate his friend. (Sing runs an emulation of parts of Sugardream to talk to the people it made friends with, since they were very attached to the point of being kind of dependent, though Sing itself does not do making friends and tries to avoid new people befriending the Sugardream emulation.)
Mars has oceans! People can be mermaids if they want! Tarinda tried being a mermaid for three and a half months once when she was 17 but she decided to stop.
New senses being hard to get used to is probably the sort of thing Sing can't help with.
Full planet sized planets within easy travel distance of the solar system are not a dime a dozen. However, not all the dwarf planets have anything on them yet, there are loads of unclaimed asteroids, and magic might make it possible to go farther and reach more planets.
The saddest person Tarinda knows is a guy whose daughter died unfrozen before Sing took over. He spends a lot of time on drugs listening to smart music but he pops out for major holidays and stuff when people invite him to things.
Mars is where Tarinda wants to live! She was born there and all her friends are there. She's been to Earth and a few other places and they're nice and nobody would stop her from moving in, but Mars is her home.
Tarinda has a friend of a friend who had 50 arms at once but it was only temporary for a particular elaborate dance project she wanted to do, usually she just has four.
You can have eyes that glow and change color if you wish!
Tarinda can't personally see UV but some people get that done.
Swordfighting is only one of Tarinda's many fighting related hobbies, but assuming she is not allowed to shift focus to unarmed or archery or something, she does also like singing and flying and hiking and watching shows and dancing.
There are many ways to classify types of biome but there are like... at least 28 according to Page, apparently. You can camp in all of them.
People on Mars think lots of different things are cool. Tarinda's coolest friend is the recreationally sinister Lord Proster, who was elected Lord on the basis of enough people thinking it would be cool to have a guy playing the villain archetype complete with a shark tank as Lord - Lord being a basically ceremonial title that means idiosyncratic things in different places, so other Lords got that way in other ways. There's one who became Lord by personally excavating the entire subterranean city she is Lord of. (Not, like, by hand, she had machinery, but she planned it all out herself and did an unusual amount of personally piloting the machinery vs. just instructing robots.)
Yes.
Yes.
Very varied! Tarinda personally is a lesbian and kinks on heroic rescues and devastatingly adorable hurt-comfort scenarios. She just likes the concept of saving sad girls from horrible fates like having lived in a pre-Sing world and then being very patient and sweet and caring till they're all better even if that takes five hundred years. She is missing this week's update of a serial she's been reading for the last 12 years.
Martian food might have some things they think is weird but they don't have to try it, there will soon be local ingredients and recipes that the robots know how to make and they can order up whatever they want. If they do want to try Martian food, though, she can recommend some stuff!
People only do jobs if they want to, basically - anyone who would rather be lying around listening to music while on drugs, or playing video games, or hanging out in a sex club, or whatever, can just do that - so the jobs that seem unappealing to most people are mostly the ones that somebody is doing out of religious or ideological conviction, or because their time horizon is weird somehow. Examples of the former are mostly living on Earth, but of the latter type, Tarinda's aware of some very frustrated mathematicians who Sing isn't telling spoilers to, presumably because it's more ego-syntonic for them to work things out for themselves.
Tarinda has not noticed things that are allowed here but not on Mars besides, like, killing people and stuff like that which isn't happening where she came from for obvious reasons. She's not pressingly aware of things that are not allowed here and are allowed on Mars though it wouldn't surprise her if there were some, everybody here is kind of trapped in a bubble together and that might lead to having more behavior strictures than you need on a whole planet.
Some people, mostly on Earth, don't want any enhancements. Sing doesn't let them be lost forever when they die but it otherwise doesn't bother them.
Sports sometimes escalate like that but often they instead get more complicated and multivariable so it's not just making a single variable go up. For example, swimming races now typically take place in extreme weather.
Lots of kinds of families. Tarinda personally has a mother, a father, two sisters, and a lot of family friends who were around when she was growing up, but people form all sorts of arrangements, and any combination of people who want to can have children. Without anyone having to be pregnant if they don't specifically value that experience.