In my DE game, you get the journal entry by reading the map of bloodmoon Island that is next to the trio by the bridge gate. You don't need a scholar tag to read it. Idk if they patched it recently.

This game is really good, but I do have to say that locking a ship npc and such a big quest (and not only this) behind just the "scholar tag", is pretty dumb.

I used source vampirism on Mor's corpse after the fight and he possessed one of my characters again.

Sonunda başardım. Cüce zincirlere bağlı iken canını bir miktar azaltın. Sürekli olarak yerde olduğu pozisyona geldiği zaman odadaki herkesi çıkartıp tek karakter ile zincirleri kırın. Ancak zincirleri kırdığınız karakteri savaşa dahil etmeyin. Cüce sizin için şeytanı öldürecektir. Sonrasında gidip cüce ile konuşun ve ardından ruh ile konuşun.

Somehow i got softlocked in Mor fight, Lohse and Red Prince are red for each other as if they are enemies but for everyone else they are green (allies)
What kind of intern developer programmed this encounter?

With Cheat Engine you can edit your Tags. I attempted to edit the String values of Tags on "Selected Character" and replace the Mystic I picked up from start with Scholar. The book was still unreadable so it didn't work. I also had Lohse in my party and noticed that her Mystic tag also got replaced with Scholar. That's when I noticed that I was just changing values at the pointers and not the pointers themselves.

Created a new character just to be able to see the pointer value of the Scholar Tag, turns out it is "00007FF4CEB427D8" (for my modded run though, might be different for vanilla). Putting that value actually allowed me to read the books and understand the contents. Proceeded into the vaults without issue.

Using Chloroform that deal dmg above the possessed dwarf HP can kick the demon out while making sure the dwarf still alive.

There's another hymnal in the worn chest near the Mordus fight.

My way of saving the dwarf without Mor possessing anyone is :
1) Have summon skill on atleast 1 character (more is better and preferably elemental summon)
2) Hit the dwarf until he loses resist death then hit him again until he is in permanent knockdown. After that heal him back to full HP and destroy 3 pillars
3) Summon a incarnate near the last pillar then move all your character back to the gate. Switch to the incarnate and destroy the last pillar and the fight will start with Mor leaving the dwarf body
4) If you are doing this solo just keep summoning another incarnate and send it back into the fight if it dies mid fight.

Some say you dont get exp for killing Mor if you just left him there fight alone and killing Mor but having an incarnate there should prevent that. You get 7225 exp for killing Mor in DE version. Yes, you get 7225 XP not 21675 XP as mention in this wiki. i tried killing Mor with my character and i still get 7225 XP. Talk to the dwarf after the fight will give you 36100 XP and his treasure location. Lastly, talk to Robert on your way out. I did not get any choice reward for all 3 vault

The dwarf's treasure gave me 3 coins...