Ah, Oh wow, A lot has happened here in the time I was away, sorry a friend offered to take care of my project for me while I recovered but it appears it was too much for her, Let's see!
The scorpion village in all honesty was created by a friend of mine who wanted to make an area, I tried to integrate it as well as I could in the story but, in all honesty, that area is a mystery even to me! Sorry I can't be more of a help there! The key to the Matriarch's home home is simply to open the door to her house if you went and killed the first scorpion girl. Since if you kept her alive she opens it for you!
Indeed a lot of doors are locked and purely decorative, I just didn't have the time to make interiors for all the houses, Maybe one day I will get back to it but for now it's best to assume most people just don't want strangers in their houses tossing pots!
The left door in the tower can be accessed once you are about to leave the last town. After Gaia asks if you need more time to prepare. It allows you to get some 'ultimate' weapons and items if you toss in the right stuff!
The "corruption" scroll and "Tsarmina" were actually a callout and thanks to my first piece of fan-art I ever received. Using the scroll from your inventory just shows the picture.
As for the glitches... Yeah, as a solo dev I struggled a lot to make it all work. I'll fix what I can but there's just so much Take down one and 10 more pop up X3
Thank you for going through this huge mess!