Thanks for the detailed feedback!!! This is super appreciated and will help me think about how to balance it!
Workshops probably have to be nerfed and the calm duration reduced to make the storm appear sooner.
I don't have ideas yet about how to solve the endgame where the storm becomes less of a threat and rebuilding becomes an annoyance. I do see that happening when the storm is far behind and resource generation is faster than the rate at which it destroys stuff, which then turns building into a chore when you're swimming in resources!