Hello, I'm AllAroundAwesome (Yep, I know it's egotistical. Call me Awe or something) I didn't think I would come onto this site to write something, but I got an idea that I didn't want to pass up. I started writing almost as soon as I got the idea for my story, The Lives of the Teenage Mane Six.
The basic idea behind the story is what issues the Mane Six would deal with as teenagers, including things like self-identity, confronting their unfolding personalities, and moving into the world. It involves all of the Mane Six in succession,does not take place in a high school setting, and starts after the ponies received their cutie marks.
What I would like help with in particular is quality. Grammar, descriptions, etc. I'm worried about and I feel like I could make the story better if I knew where to start.

I'll take a stab at this one for you.

Give me a couple of hours to read it and write up a list.

Getting into it now.

Review for Lives of the Teenage Mane Six

Short review
Pros
1. An interesting take on a glossed over topic
2. Good weaving of the characters together, given that they are not meant to know eachother well until Season 1 starts.
3. Well detailed plot

Cons
1. Structure of the chapters can be hard to follow
2. Large walls of text
3.Plot meanders for a while, not actually progressing very far for the amount of words used.

In Depth Review

Story
The basic story for this fic was quite good - I haven't seen may, if any fics that deal with the direct period of time after the mane six got their marks. I thought that you were able to handle the new interactions between the mane six well, while also being able to focus on the assumed relationships between characters like Pinkie and the Cakes.

The sub plot budding romance between Applejack and Rainbow Dash was nicely handled - the right amount of arkward and sweet from Applejack, with the brash nature of Dash.

Due to the inherent nature of the six parallel stories, it does seem to take quite a while for each thread to actually go anywhere. Rarity's story expecially seems to be dropped for several chapters

I thought that the section about the Oranges not servicing Ponyville seemed a bit far fetched however. They are still one family unit afterall, and dealing in different products that would not compete.

A few nice references later in the story to other fan products like the Turnabout Storm series - Ace Swift

Characters
I like your take on all the characters. Setting this story in the period between the flashbacks and the actual show means that you can disregard most of the show's dynamics and insert your own in their place without having to explain away too much. It is nice to see that the characters do in fact know each other, even if it is just passing meetings.

Twilight's mini freak out as she began to cave under the pressure of studying was fun to read - having her believe that the books themselves were tormenting her.

I liked the pressure that you were able to exert on the Cakes and Pinkie when they were trying to bake the Orange cake, but I also feel that too much is being made of Pinkie's identity crisis - just have her be happy for a while, or have her break and be Pinkamena again.

Grammar and structure
Your actual usage of grammar itself is quite good - usage of question marks, quotations, and exclamation marks all check out as far as I can see. You did tend to overuse exclamation points in a few sections, which can detract from the impact of each one.

And there he stood! At the doorway of my parent's house! To see my dress! I almost couldn't hold myself together.

Three exclamation points is a bit excessive in this single sentence. The one after 'stood' could be a comma rather than a exclamation.

Structually, this fic needs work. While you have followed correct procedure and given every new speaker a new line and used indenting, it still reads like one large wall of text. Try to add in an additional line of spacing between each new line, as this will break up the passages into smaller chunks that are easier to follow.

I went upstairs and thought about how I got to where I was. I mean, going from a rock farm to a bakery is a pretty major change! And it's not like I didn't anticipate that I needed a change in scenery. I already knew I didn't fit in with my own family. I was just that odd filly in the group. I wanted to bounce around, they wanted to work and earn money. I wanted to create things with the rocks, they just wanted to sell them. Add in the color factor and I looked more like an adopted daughter more than anything else. This, along with my cutie mark being so far away from my family's professions, led me to leave in search of a better life. My parents didn't take it very well, but they knew that truly it was the right thing for me to do. They did keep me until the off season so that I could finish off work, but I could never hate them for that. After all, they still needed me. So I left as soon as we had gotten all of the product of the farm, bouncing off the walls the entire time. My sisters... didn't take it as well as my parents took it though. Inkie and Blinkie refused to come see me off. I guess they saw me as betraying the family that had raised me and betraying them as a big sister. I really wish I could have told them all about everything that I am, then maybe they would understand especially since they don't know what their purpose is. I wished they could've seen what it was that I wanted to do in an actual light and not just a spontaneous party.

Becomes

I went upstairs and thought about how I got to where I was. I mean, going from a rock farm to a bakery is a pretty major change! And it's not like I didn't anticipate that I needed a change in scenery. I already knew I didn't fit in with my own family. I was just that odd filly in the group. I wanted to bounce around, they wanted to work and earn money. I wanted to create things with the rocks, they just wanted to sell them.

Add in the color factor and I looked more like an adopted daughter more than anything else. This, along with my cutie mark being so far away from my family's professions, led me to leave in search of a better life. My parents didn't take it very well, but they knew that truly it was the right thing for me to do. They did keep me until the off season so that I could finish off work, but I could never hate them for that. After all, they still needed me.

So I left as soon as we had gotten all of the product of the farm, bouncing off the walls the entire time. My sisters... didn't take it as well as my parents took it though. Inkie and Blinkie refused to come see me off. I guess they saw me as betraying the family that had raised me and betraying them as a big sister.

I really wish I could have told them all about everything that I am, then maybe they would understand especially since they don't know what their purpose is. I wished they could've seen what it was that I wanted to do in an actual light and not just a spontaneous party.

Additionally, your use of colour coding the first few words of each character change, while a nice try can be a bit hard to follow if you are not concentrating hard, or if the reader has a colour blindness. I would have done that as using the page break followed by the name of the pony who's perspective we would be following next.

"Have a good night Applejack. See ya tomorrow."

I flew home with a slight blush on my face. I couldn't wait to go to sleep for once because I knew it would bring me closer to the time Applejack and I meet again.

---

Applejack

Rainbow Dash. She literally fell into my life. She's brash, cocky, impatient, and annoying. She has so many faults to her.

So why is she so irresistible?

TL;DR Summary
Fic is not bad - interesting plot, lively characters. Needs work on basic structure to make it more readable.