1. Remove "Apply to construct a guild castle" from NPC dialog. It's simply not needed there. The castle is constructed once and Varanas Guild Hall is the perfect place for this. The first option should be entering the castle.
2. Please add auto flipping the treasury switch after one closes the guild bank. It's really annoying to wait every few seconds when you come to use the vault. First you wait to close it after the previous user. Then you wait to open it for yourself.