I don't see stealth missions working in this game that well, they had these missions in The Secret World and they were the most frustrating missions ever. I really don't want to go through that again.

However I think tower defense would be fun and could use DoH/DoL classes to help out. This can be something like Besieged, but a nice new and up to date.

Other than that, I think most of the missions are fine but some overworld quests that involve parties to complete would be welcome