How do I progress in the "Mori Mountain Estate" mod?

According to this page, there is no "questline" of any sort included in this mod.

As for the dungeon :

SECRET CRYPT is just a regular hack and slash with several bosses that drop interesting (balanced) items (I'm a purist). The crypt is intended for level 20+ characters but it can be done at lower level if you're careful.

The two NPC, Zippy and Nami, are interesting though.

Zippy the ingredient sorting mouse, just click and zoom all the ingredients in your inventory are sorted into the jars.

Nami the Librarian will auto-sort all the books in your inventory. Just talk to her like you would Zippy and in the blink of an eye she makes duplicates of your books, places the copies on the shelves in a nice orderly fashion and places all the originals into one of three alphabetized closets.