1.This doesn't happen in first language option. It happened because of misplaced "," in second language file for her NPC.
2.They should be, near 305. I didn't add right "Y" position to those cloths.
3.Those are not bugs. I'm planning to add a separate application for making custom mods and these artifacts will be helpful.
4.You need to have two Masuo at your front door for that scene to appear. You might need to cycle through all truck assistants. Each time you reached no assistant state the game tries to get different activities for idle custom assistants. Since they don't appear directly you will need to go to a map and return see if their activity is different.