Hi
First of all events are a great feature of the game spicing things up. I think you should re-consider the building discount events.
The game should be about strategy. E.g some people might choose to go for a defensive strategy while others may opt for at attacking strategy.
With these...
I think you should consider hos the building discount events affect the game.
The game should be about strategy and I find these events unfair and affect the gameplay in a negative way. Take the last factory/aitstripevent. I global age without any discount one had to collect 210.000/200.000...