Addressing some points that were brought up in the video:

Cover Art Source — Oh my word. I still periodically get questions about where my cover art came from. Someone just commented on a recent chapter of Anzel's story with this question. wkjthkrtkjhertkjah

While I also don't like clutter in descriptions, I totally understand why people might prefer to give outright credit there than using the site's built-in functionality... because people will still ask even if you use the site as intended.

Indents / Online formatting — This definitely varies from person to person. In printed format, it absolutely should follow the standard of no extra return + indentations. Online, however, because of varying screen resolutions (giant monitor vs. tiny smartphone) I find it much more reliable to go with no indentation and extra line space. It's easier to read on big screens, where the width can far exceed a printed page and cause a chapter to look like a gigantic wall of text, especially given that, by default, the line spacing is not reading-friendly for large swaths of text.

"dug them up" — Ahahah. ^^; I totally had the same mental image. "um. UM. Rainbow Dash, I know you destroyed a weather factory so your moral compass is a little askew, but digging up graves is a little lot not okay!"

Show vs. Tell — This is something that is touted frequently to new (and not-so-new) writers. Yet, just as frequently, it's not explained in a way that makes sense or is tangible for folks to latch onto and learn from. You gave great examples of how to show emotions rather than tell them. Ponies and their ears and tails are great ways to express things—pinned ears, drooping ears, swishing tails...

Characterization (Apple Bloom) — The "Dude" threw me off, as well! It's really important for people to use both actions and dialogue as opportunities for characterization. If you took out the dialogue tag, I'd have no idea that was Apple Bloom talking. Very important for people to keep in mind while writing.

Genre — I agree; it was very dark and mysterious. It felt like a German fairy tale. I appreciated that it didn't go edgy/dark, but kept a distance to it that allowed the suspense of dark rather than the overindulgence in dark.

One note that I don't remember hearing brought up was speakers and paragraphs. There were a lot of cases where a character's actions and their dialogue were in separate paragraphs. These should be grouped for clarification / flow. An example that stood out to me the most:

“Good. Now, I’ve got the worst ghost story of them all. This is the tale of the haunted mansion!” Diamond said and everypony groaned. Diamond frowned.

“Haunted Castle?”

I assume, given the surrounding context, Diamond is the one who changed mansion to castle, but it's not clear because of the paragraph break.

You guys did a wonderful job being fair and, at the same time, educational. This wasn't a scathing review by any means, but was actually very helpful IMO. I hope folks give this a good listen-through and learn from it. ^^ You're both also just fun to listen to!

I liked the casual nature of the 'review' as nothing was too serious or silly.

Have fun, drink some beers, do spontaneous rants, and just read/talk about pony stories in general. Sounds like a winner to me.