Defender of Varrock: He directs you Camdozaal by giving you a Scrap of paper with coordinates on it.
The Giant Dwarf: If you take Dwarven battleaxe(with gems) and an Iron bar to him he will fix it for you. It is possible he will ask for a Redberry pie in exchange.
The Knight's Sword: Give him a Redberry pie to get him to talk to you. He will need a picture of the sword, 2 Iron bars and some Blurite ore to make a duplicate sword.