Some suggestions:
1) Quality rooms. Have rooms generate as normal (white), blue (slightly harder/better), yellow (harder/better), and purple (really hard/better). So then it would make for more interesting exploration and more consistent ways to get really rich or really powerful quickly.
2) Able to upgrade the blacksmith. Each upgrade reduces costs by say 10%, and adds an extra item to be sold whenever visited.
3) Combo Rooms. A room with two symbols on it. So say a double sword and a healing symbol. So everyone is healed on entry and then combat ensues.
4) Elite monsters. Higher xp and loot, but tougher.
5) Continue exploring. Allow a group to stay on the current floor, to keep exploring, rather than either forced to retreat or descend.
6) Allow heroes above level 7 in graveyard. However, make it so that they earn level disparity * 25% less xp. So at level 9, they'd earn -50% xp. This way you could use a higher group to farm low-level equipment for a fresh party.