Brut e is the vocative case form. Brut um is the accusative -case form. Brutus is coming. And since the direct object of the common verb for I see is put into the accusative case, you would have to say Brutum video. I see Brutus.
Carpenter is the subject , the agent that performs the action of the verb.
Us is an indirect object here. House's is a noun indicating possession . We are speaking about the door that belongs to the house.