Oh Yeah! Make it Either an Evolve, or Increase Percentage of Time Reduction by Lev it is Upgraded .... Could make it Look like a Mini-version or something Similar to what the Spire looks like.. Or even make it follow the Theme of the Event Buildings The Spire Building is Awarded in { for...
#2 Instead of Copywrit-protected Creatures, maybe Treants Race(From Barracks)??
#5 Maybe a "Secret" Door to a Different Path.. Possibly Discovered at some Point along the Existing Hallways??