Salacberry

This is a fun idea! I played around with Sweet Style a bit and came up with this, but I haven't coloured it in. The streaks in her hair would be pink, maybe with a peach or orange colour as well.

Funnily enough, a few days ago I redrew my OC, Sweet Style, and tweaked her design slightly in the process. The changes aren't extremely obvious, but most significantly I made her 'default' mane style the one that was originally her alternate mane style, because the original was a bit too Applejack-y for my liking. (it would have been okay if not for her freckles and yellow hair!) I decided to keep the pink bow, but moved it to a different position. The smaller changes are a bit harder to pick up on, but if you can tell, I gave her mane more volume, removed some lines in her tail (because it was originally a bit too complicated) and changed the colour of the camera flash in her cutie mark. (because the original colour wasn't featured anywhere else on the design and looked strange) The new design is on the left! See if you can tell the difference.

I would love to see Lily Blossom make an appearance! She has a really lovely design, which also happens to be unique! (she's not a recolour of one of the mane six, which is rare for the toyline) I'm definitely interested in seeing what her personality is like.

I do think that the other races would gain wings if they became bat ponies. I know this isn't the best example, but when the mane six transformed into Breezies, all of them got wings. Obviously the circumstances were different, but it is notable that Rarity received wings despite being a unicorn, and that therefore she technically had both magic and flight while in that state. Just as wings are a defining characteristic of Breezies, I believe that they are also a defining characteristic of bat ponies. My reasoning clearly isn't completely valid, but yeah, I do think that a pony that transformed into a bat pony would have wings regardless of its original race.

I think the majority of OCs are unicorns or pegasi because people are enticed by the prospect of flight or magic, which are exciting because they are not human abilities. However, ultimately, the merits of a character are their personality, backstory and development. Race should not be the defining trait. Personally, I think those that view earth pony OCs as 'boring' seem to be focusing on the 'flashy' attributes of their characters rather than the actual substance. If the difference between boring and interesting is the presence or absence of flight/magic, this indicates that perhaps the character needs to be fleshed out more. This is why it is often seen as more challenging to roleplay as an earth pony; you can't rely on flashy abilities to define your character. Of course, there is absolutely nothing wrong with having unicorn and pegasi characters- I have some myself. But my main point is that your OC's race isn't their most important characteristic. Earth ponies are not automatically boring; it's up to you to make them special in your own way.

Hearth's Warming Eve. To be honest it wasn't really my cup of tea, and I found it a bit boring. I think it's the only episode I haven't rewatched.

Aria is my favourite. I like all three, but Aria has the best design and I like her attitude. Plus, she's definitely underrated.