Are there any resources available for playing variant half-elf with traits from specific parent elf type?

I would like to find extra info/histories/details on the Sword Coast cities Resources?

Will Xanathar’s inculde subclass options printed in Sword Coast Adventure Guide?

Is there any particular reason why we’ve never left the Sword Coast?

Is Sword Coast Adventurer’s Guide an updated version to Ed’s Grand History of the Realms?

Green Flame Blade, Post level 5, can the additional d8 of fire be effected by a crit?

If I cast Green-Flame Blade and use Divine Smite, does the smite apply to both creatures?