User blog comment:BannedLagiacrus/Monster Ecological Info/@comment-9290318-20141123195635/@comment-6050823-20141123201252

1) Its unknown what exactly happened to everyone in Castle Schrade but the cause of its destruction was Fatalis, leaving the kingdom a ghost of its former self.

2) No idea as of yet since White Fatalis hasn't been released in MH4G yet.

3) Crimson Fatalis did as well, according to a quest in MH4. The G-Rank Crimson Fatalis(MH4G) is even stated to be a Black Fatalis that was defeated in Castle Schrade before fleeing some years ago and reappearing in the Lava Island some years later.