I like the idea but there are still differences no matter how you spin the Events:
- You wouldn't be able to trash the card later, i.e. no trash-for-benefit effects
- They wouldn't run out, like how supply piles do
- They wouldn't contribute to 3-pile endings
- They wouldn't bump up your Gardens, Fairgrounds, etc.
- They wouldn't be something to discard after you've drawn your deck (Horse Traders, Vault, Secret Chamber)
So although the idea of having the Events instead is cool, they would certainly change some game mechanics.