There is nothing you can do right now, its too late for reseeding, if that turns out to be necessary. Its also probably a bit late to flush the lawn with water to dilute the worm liquid, as the grass is already turning brown. The only thing you can do is check it again spring, and reseed any bald areas at that time.

The brown spots will fill in. How soon depends on what your winters are like. No need to do anything at all. Just keep it moist.

Wow! Worm casting tea is usually pretty low calorie. Was there something added to it?