Oh come on!
I finally get an idea for how to deal with that creep and he goes and takes off! Seriously, how inconsiderate can you get, after all that effort I put in to get everything ready he just up and leaves before I can get him.
Does he have any idea how hard it is to stay solid long enough to herd chickens?
And for the love of Celestia can they stop with the damned rainbows? Yes we get it Rainbow Dash you can murder foals every day and display them in front of us and we don’t even know, hardy har, can you seriously ease up on them over ponyville, I can’t even see the bucking clouds half the time.
How has no one noticed this?
Why hasn’t Luna done anything? She hasn’t been to my grave this week and she doesn’t even seem like she’s done anything to look into things. Maybe she doesn’t care about me after all.
Guess it would make sense... Rainbow Dash showed me exactly how worthless I am... I can’t even die properly/
Why does she not go and check up on Princess Luna?
2833898
Scootaloo can't venture outside of areas where she frequently visited in life or the Rainbow Factory, her place of death.
2833906
Can Scootaloo float over to Rainbow Dash, turn solid long enough to give a decent buck to the back of her head, then stop being solid so that there is nothing Rainbow Dash can do about it?
2833990
Aside from the fact that, as the image shows, she doesn't even have hind legs anymore, would you really want to go back to that place willingly, even if Scoots didn't have some pretty clear self-loathing right now?
2833898
She is a ghost - ghosts are sentient beings who stay behind after death because of their emotional turmoil. Don't expect them to be rational.
2833999
Personally, I would go back there once. As Rainbow Dash would be feeding a foal into the machine I would dive at her, using my hooves to hold her wings to her sides while making my torso solid enough that I could use the speed from my tackle to knock her onto the machine. Stay there holding her wings down until part of her gets caught in the machine, then leave. Scootaloo can not be physically hurt by the machine anymore so that wouldn't be a problem, and we know that the factory is always filled with the screams of small children, so unless someone was watching, no one would hear her screaming to stop the machine. Then, even if Rainbow Dash did turn into a ghost, Scootaloo has the experience needed to inflict even more harm upon Rainbow Dash. VENGEANCE COMPLETE!!!
2834079
There are a few hitches to this plan, at least in this canon; first off the Pegasus Device doesn't just dump foals in it, you'd need to very deliberately lock someone into it. Secondly, Rainbow Dash could just fly off, and even if Scoots could hold her wings Kuleco or one of her other lackeys could turn off the machine.
Also, vengeance is often a hollow victory my friend. She kills Rainbow Dash... so? Kuleco would just take over and it doesn't restore Scoots, at most all she does is get stuck with Rainbow Dash for eternity.
2834048
Not entirely true. Ghosts are souls that didn't move onto the next realm/life for whatever reason they might have. More often then not it is because they have unfinished business in whatever realm they are currently in, they wish to stay behind and safeguard something of significant value to themselves (often they become poltergiests), or they need some self thought before they are content with their lives and then they move on. Emotional turmoil is only one of many reasons why a soul would stick around for a while.
2834079
She already has all the tools she needs to drive her crazy at least - also, all the reasons for ghosts to appear that you listed include feeling strongly about something or being obsessed with something.
2834140
True, however, I said they were the most common options, not the only options. In a world full of magic, that brings in a large number more possibilities than there possibly could be here. It is possible that, when Scootaloo died, her soul grew some sort magical attraction. It would stand to reason that, because Scootaloo never flew, all of her Pegasus Magic stayed in her body and, due to the immense build-up of magic, caused the Pegasus Magic to collapse on itself upon Scootaloo's death, causing a black-hole effect. This would cause Scootaloo's soul has a constantly growing field of magic around it. The magic casing around her soul would be connected to the soul to some degree, meaning that her soul would have some form of "physical form", and the "physical form" wouldst keep her tied to the realm she lived her (admittedly short) life. The black-hole effect around her soul could very slowly attract magic while compressing it into the area immediately surrounding her soul. She gets rid of the magic by becoming solid, so, theoretically, if she stopped becoming solid for long periods of time, the magic concentration would be detectable by creatures finely attuned to magic (specifically, Twilight and Luna). However, due to the fact her soul is constantly absorbing small amounts of the ambient magic in the air she could not truly run out of magic and be sent on to (whatever happens after death), she would always have tiny amounts of magic in her.
This also explains why there are no other ghosts (they could and did fly, they just really, really sucked at it). It also proves that Rainbow Dash would NOT turn into a ghost (at least she wouldn't be the type of ghost I just explained). Rainbow Dash bleeds out Pegasus Magic at a rate previously unheard of to anyone EXCEPT the Wonderbolts. She needs magic powerful enough that, with the right motivation, can break the sound barrier, and can prevent her from being ripped piece from piece from the sheer force exerted on the body from going that fast. Also, she LITERALLY leaves a trail of magic wherever she flies (in the form of a rainbow trail). Therefore, it is unlikely that Rainbow Dash would become a ghost through these means. If Rainbow Dash were to become a ghost, all Scootaloo would have to do is hop onto RD's back. RD could not reach back there, ghosts can not phase through other ghosts, and no matter how fast RD flew, the air would just go through them unless one turned solid. As Scootaloo hangs onto RD'S back, the magic black-hole around her soul would slowly absorb all of the magic binding RD to that realm, therefore forcing her to move on (to Tartarus).
Yes, I do enjoy greatly over-thinking things.