Is there a page where the first dialogue tree with this character is displayed? If not does anyone have the consequences of each answer in this conversation? Also I feel this is a missed opportunity in the game as this character would fit well as a lookout for your haven for you or your antagonists. Well as it is he seem to be another bloodbag but I would still like to have the first conversation I have after the tutorial in the Wiki?
The bum is actually your first "Humanity check". If you give him some cash, he will thank you and you will gain one point of Humanity. If you don't help him and insult him, you will lose one point. His role is to teach you that if you are a kind individual, you will manage to control your vampiric urges and be closer to your human self, rather than your Bestial self.