Let's say if somehow SCANDAL didn't get into music, then what do you think they would become?

I think HARUNA might become a dancer since her original dream was becoming a dancer. She might also become an actress since she used to has a minor role in a movie, although this chance is slim.

TOMOMI might be a dancer too since she had the same dream as HARUNA. Also, I think she is qualified to become a MC since she's funny and active, and her voice is perfectly suitable for MC'ing game shows, for example.

MAMI might become a painter or designer since we all know she has a good drawing skill. Her drawings are featured on many SCANDAL's items such as T-shirts, stickers, keychains, etc.

About RINA, I'm not really sure because she has many different types of hobbies. She might become a photographer since she's very interested in photography. I can image how her photography style is. It should be vintage since she loves the 60's era. She might be a restaurant owner since she wanted to try serving people at a restaurant; but this chance is slim though. Another chance, becoming a piano teacher (this is not contradict with the topic title since piano teacher is different to getting into showbiz.) Anyway, if RINA could not find a job suitable for her, she could always become my wife.  .love.

I could see RINA being a well-versed movie critic!

^I agree.

Anyways, the girls were asked a similar question at the AM² Panel in 2011. This is what they said: 

Mercurius wrote:Q: If you were not in a band, what would you be doing?
H: Never really thought about it, but because I'm a music lover, it would have to be something music-related.
R: Baker
T: Care-taker / day-care worker (some confusion since Tomo said "hobo-san" not knowing it sounded like the English word for homeless, so it sounded like a joke until translator clarified)
M: Designer

In case you're interested, here's a link to the other questions they were asked.

Without taking the Am^2 answers into consideration I would think the following:

Haruna: Fashion designer/model maybe? looks like haru is the most interested from the 4 in fashion and specific brands

Mami: Atelier? I think she might make clothes based on what she has recently been doing, but other than that maybe entertainment? She is so funny lol

Timo: I think she could be the perfect replacement for something like the host of J-Melo not sure what the job title would be but she is very cute and has very funny moments lol

Rina: Movie critic like someone said above is pretty good!

I really don't know the girls that well yet, but from what I've gathered in my short time:

Haruna - She appears to really like singing, and I think her passion for dancing is still there, I could imagine her being in a girl group, rather than a band.

Mami - Seems really intelligent, articulate. Maybe not necessarily a clothing designer per se, but definitely something where she gets to share her ideas, graphic designer, advertising perhaps.

Tomomi - really seems to have a love of food, and I hear people tease about her cookie infatuation, so her wanting to be a Baker totally makes sense. Also someone above mentioned showbiz - she totally has the charm for it.

Rina - she comes across to me as being a really passionate person, and someone who would want to share her love of things, maybe in a teaching aspect, even a tour-guide.

All talented girls, I'm sure if their music careers didn't last forever, they're all very capable to pursue their alternate dreams, whatever they may be.

Haruna - She seems more Showbiz type to me,  she was in a dancing movie and a play, so maybe an actress.  But she has to use the wonderful voice some how,  I say an actress who stars in musicals.  That way she can both sing,  dance,  and act,  all riled up to one.

Mami - I read in an interview that she wanted to become an architect.  But yeah something Design related.  She's a really creative person,  and can come up with things in a snap.  So maybe a Graphic Designer, Character Designer, or something relating to comic book or video games. Though it's kinda hard since she was practically born to play guitar.

Rina - this one's kinda easy to me,  she likes to read a lot,  she watches movies a lot, she takes pictures a lot, and she writes a lot.  Like someone said above, she's a passionate person and seems the type who would voice her opinion about things. So maybe something in the Media,  like a reporter or Photographer.  But I thinks she would do very well as an Author, she reads a lot, her blogs to me a basically like poems and stories, she a good writer, plus she even has her own book named one piece. She would also take pictures and incorporate them in her novels.  

Tomomi - ah, she's a cheerful girl who likes food a lot. Over here, we have shows about a person going around different places and trying out different foods and rating them.  So I think she would do the same thing,  it would show case her upbeat personality plus she gets to eat different food for a living, it's 2 for the price of 1Ｏ(≧▽≦)Ｏ It always seems like Timo is the the one trying out different food and beverages whenever Scandal go on shows,  so why not make that a job? I'm not sure she's a critic type person,  but she'll have a lot of positive things to say.  
Though she would probably want a partner, can't think of anyone else than but Mami c.han^o^

Haruna may have been an actress or a R&B recording artist.
Tomomi may have been a real estate agent or a flight attendant.
Mami may have been a couturier or a painter.
Rina may have been a chef or a music teacher.

This is under the premise that they never met in caless

Haruna- Agree with everyone, she seems more the show business type. She could be in a dance group and still take the position of center.

Rina- Music, she'd pursue piano or guitar. Or photo blogger, somewhere inline with interacting with people.

Mami- She seem the quiet artist type. If not in the world of arts she could be an advice columnist. Or she could end up making doujinshis, both story and art.

Tomomi- If not show business, she could be a travel writer. She could do anything really just as long as she's not confined in an office environment, to tomoimasu.