H!'m going to write some/a lot of a…'fan' fic, featuring an adulterated version of Mac, AJ & Co.* (ie OCs). I intend to weave in CCs, but I am not comfortable doing canon characters. Therefore, I seek (a) co-writer(s) to cover the parts of CCs - dialogues in particular and authenticity in general - including firm, fan-based feedback on if they may be plotted in at all.
*currently "Pink Lemonade" & "Petite Rose", the latter the adopted sister of the former, and both 'cursed' with hormonal growth issues, the former unusually large, the latter a 'minipony'. They in turn foster/adopt a little foal - filling in for Bloom - and his Aunt moves in, taking the role of Granny.

I am fairly early in the plotting stage, but I can say which CCs I am most interested about incorporating. I ship RariMac - the sophisticated city lover and a simple country bumpkin, just strikes a chord with me - so I've her situated in the plot as recommended by another CC for acquiring a dress that is needed for 'AJ' to attend a fancy do...and as a crush/object of lust for 'Mac'.

   Gilda and Zecora follow. Tempest Shadow is of particular interest, what with her broken horn, but I've gotten the idea that she's not contemporary to the Mane 6. If that is true, I would not make use of her, as much as I would like to. I will not use any CC that is not reasonably fitting for their purpose in the plot, so how the CCs finished up in the official series, is of great importance to me.

   I would like to incorporate at least one royal, naturally. Celestia and Luna are about equal as to my preference, but the latter - with her ability to cruise dreams(?) - seems slightly more likely/fitting. Cadance(& Shining) next, followed distantly by Twilight(depends on if Spike ended up with her in some way).

Trixie & Starlight Glimmer last, but the former should probably be higher up. I have always had a soft spot for Trixie, based on my impressions of her. Travelers/wanderers are more mysterious and romantic, I think.

I admit I would also be tempted to do something with Sugar Belle, but I feel that is 'playing with fire' given that the canon is pointed right at the pairing. I will leave it as a remote possibility, 'til I should definitely decide against it.

And too, perhaps various supporting characters in and around Ponyville. I am of a mind to situate my knock off Apple family in a nearby town, but if there is not a canon possibility in line, then I may just opt to situate them on another produce farm very nearby.

Oh. The real Apple family. My lead stallion OC may have gone to school with Mac or AJ. And/or having grown up in the farming business, it is only natural they should be acquainted. I am not hot to include them, though.

Probable Kinks/Themes are:
Size Difference
Transformation(up/down-sizing)
Huge Testicles
Ridiculous Dick
Sm. Dom/big sub
Lactation/Milking
Ball Worship
Femdom
Naughty Royalty
Herm Alicorns
Dismember Portal 
Dub Con/Regret
Half Castration
Castration Threats
Castration Play
Ball Busting
Spanking/Hoofing
Luststruck Sibling
Age Regression?
Objectification(phantomare)
F/F, F/M, M/H, H/F, perhaps a little M/M(I can only see it being Shining, at this point, and as Maledom)

The full backstory and plot will have material for a lot more, but I intend to trim the actual writing down to 20-40k words. That will be quite enough of a project for me, instead of turning the whole thing into a hoofing epic(which has always been my tendency).

And, yes, as the Thread Title implies, I am willing to pay for my help. Not a lot. I shouldn't drop $3-400 on this. I am looking to cap costs off at $1-200, but I will stretch to $3-400 if the CC part of the content is considerable/if the word count tops 40k & especially if the writing of it stretches well into the next year(Feb./March+).

Please contact me if you might be interested. Or check out the G.doc filled with my questions about FiM.
[Some are naughty in nature: https://docs.google.com/document/d/1HSt75NJTPH1FZulA1NCdQlKk8urq2c-sD3N2MWmrgvY/edit?usp=drivesdk ]

Hay! Thanks fur reading!
~ X

It's a shame it seems like you're interested solely in a no-consequences sexual romp through the mud, since I'm all about romance, real life consequences for the character's actions, and healthy relationship dynamics.
Like... It's almost impressive, though I'm curious, if you're openly advertising your interest in writing noncon (rape), age regression (pedophilia), and other semi violent themes, why are you burying the lead of incest? It seems fairly obvious by your character layout that you're trying to justify incest while avoiding blood relations, or is that not part of the story you're looking to write? Not saying there's anything specifically wrong with those themes outside of a sexual context, but in a sexual context with no consequences it becomes pretty dicey.