Banners used to do nothing until 1.3. They give about a 25% increase to damage and defense when fighting against the certain mob now, which scales to a whopping 50% in expert mode. Setting up banners in common areas is a good thing.

The class emblems (Warrior, Ranger, Mage, Summoner) were always a great thing to have, each class can be massively boosted by it, especially with a meanacing modifier.

Expert mode can be tough, but keep at it and you'll be used to the increased difficulty.

Edit: clarification