Skyrim's final major DLC might not have as much cut as some parts of the base game but there was still a noteworthy amount, a lot of which is sadly in a pretty broken state - not all of it though! Plenty of what was cut actually left me wondering why because it all seemed good to go. All the new stuff included is actually already in the files and I just implemented it:

Dragonborn (Solstheim)
Solsthiem ash mudcrabs (unused NPCs) – new mudcrabs on Soslthiem that have had a styleup.

Glowing and pack spiders (unused scrolls and NPCs) – These two spiders are nowavailable to craft at the imbuing machine. They follow you around. One has 8 legs and a few could be spared to carry your burdens whilst the other glows like a torch.

Horker Youngling (unused NPC) – not just the horker men but the horker women and children too.

Storm, Frost and Fire Flow (unused spells) – now available at Tel Mythryn.

Telvanni Banner (unused item) – Tel Mythryn looks a little more Telvanni now.

Castle Karstaag icon (unused map marker icon) – now with a unique looking map icon.

Castor the Puzzlemaker and bandit (unused NPCs) – Two corpses added to Damphall. Yes, that’s it.

Netch poison (unused item) – now available at Tel Mithryn Apothecary.

Red Mountain plume from Skyrim (created location) – that mountain you can see beyond Skyrim to the East is Red Mountain, the same one that’s visible from Solstheim. It never made any sense to me why it was smouldering from one place and not the other. Now the plume no longer magically disappears and can be seen from the mainland as well.

Part of the Re-Cut series - I will add links as they are uploaded:
Whiterun
Haafingar / Solitude
Hjaalmarch / Morthal
The Pale / Dawnstar
The Reach / Markarth
The Rift / Riften
Winterhold
Eastmarch / Windhelm
Falkreath | Granite Hill
Dawnguard
Dragonborn / Solstheim (you are here)
Miscellaneous
Anniversary Edition / Creation Club
Skyrim | Skyrim Legendary Edition
Into the Abyss - not officially part of the series but features a couple of cut levels that have been a bit repurposed as they didn't fit in Re-Cut.

Q&A
Aren't there other mods that do this?
Yes, absolutely. There are plenty of good mods that do this already however none of them seemed to be as extensive as this one. I have literally added almost everything I could find that wasn't straight up broken or heavily reliant on a removed quest. Some parts have also been done a bit differently as there's almost nothing left of some parts so a little personal interpretation had to be used. This is also part of a series which is broken up into pieces so you can pick and choose which parts you may or may not want to keep, so if Whiterun conflicts with too much for you but you still like Hjaalmarch you can keep one and remove the other.

No quests?
Not at the moment, sorry. I think there's a reason a lot of the cut quests haven't been touched and that's because it's like trying to assemble a jigsaw in a foreign language with no instructions and plenty of pieces either being wrong or missing. That also includes almost anything to do with the Civil War. There are already some mods that do a lot of that and it would take an absolute Creation Kit master to be able to restore some of the stuff that hasn't been already.

You missed something and I am sad it's not here...
If you think that, then great. Not the sad bit but rather that if you found something I did not then please tell me about it and I'll see if I can implement it.

Isn't this all just removed cut content added back to the game? What do you mean by your tags of "cut, unused and created"?
Cut means you can find reference to it in the files or other sources like the strategy guide but wasn't literally present in the files. I tried my best to recreate it how Bethesda may have done but can't guarantee it's 100% how they would have done it. Unused means I basically just put it back in the game because it couldn't be found anywhere in the in-game world. Created means I added it in myself because it was just logical, such as an inkeeper to an unused inn or Thalmor in the Thalmor Headquarters. I have tried to restore everything as faithfully as I possibly could but some of it simply had next to nothing left to work with and required some of my own input.

Compatibility
This mod should work on pre-existing saves and be okay to install mid-game.

I actually made sure that it would work with a few other popular mods like all of the Creation Club content, the Unofficial Skyrim Patch, ESO / Legends Imports, Populated Skyrim and a few smaller scale ones like Khajiit Caravan Mules. Should be pretty compatible with most mods as this one is mostly just some lighter changes again - everything in it is already in the files and just unused aside from the Red Mountain plume which is just the same as the one in the base game anyway.

It can work on any version of Special Edition as it doesn't use anything from the Creation Club but if you're not playing one of the latest versions of Skyrim you will need a mod like Backported Extended ESL Support for it to work properly.

More questions?
If you want to tell me anything, have any more questions or want some help or whatever then feel free to message me here or on Discord.