Some problems there I think.
The Burn is between Garlemald and Othard, not Ala Mhigo.
Cid didn't make that thing, the Sharlayans did, we dug it out of the Gubal Library.
A flood of light, to our knowledge from 3.4, isn't just some big aether explosion.
Some supposition but I think the outcome of the Crooked Coin being overloaded is more like to be like the end of Allagan Empire. It's basically an aetherial electrical grid substation and the vast majority of them were overloaded when Dalamud was hooked up to the network, blew up, and caused the "Calamity of Earth."