How to make a custom structure and world generator.

The first thing I am planning to make is a custom structure generator that uses WorldEdit schematics ​

to place the blocks in the world above ground. Let's say a new temple that goes in the Taiga biome. I want to randomly place that schematic in 1 of 10 chunks out of the Taiga biomes in the world. How could this be achieved?

The second thing I want to know about is how to do a custom world generator now considering the tutorial by Dinnerbone is a little outdated by now. If anyone had played The Nexus factions realms they would know what I was meaning by custom worlds. I want to make my own biomes and add my structures in to the world with the above question answered. The biomes that I add in the world will have their own custom trees and other random structures you might see in the Twilight Forest Mod a little random I know but that mod has a lot of great stuff in it that I would like to use in bukkit without new textures and other stuff I can do myself at a later date.

I know what to do on the first question but the second was not answered on spigot.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.