There are several reasons why there aren't tutorials for things like this.
One is that some people follow tutorials without understanding what they're actually doing, then it breaks and they don't know what to do. Really, they shouldn't have been building something that complex with their modding experience.
Another is that once you understand the basics of something, you should be able to build complex things yourself without a tutorial. If you need help, that's fine, everyone does once in a while; but if you need a tutorial to hold your hand for something complex, you shouldn't be building it in the first place.
I believe that a "tutorial"'s purpose is to guide someone through a process. Yes, this can lead to people mindlessly writing lines of code. For the small group of us who have taken the initiative to actually learn how to code one of the most complicated coding languages in the world, detailed instructions that describe how to create a new dimension, a new biome, the animated cupboard that took 8 classes to get working, or even things more complicated than that, one good tutorial could change the course of someones interests.
Add Jabelar's tutorials, they are mostly for 1.8+ but cover some things that are the same between 1.7.x and 1.8+
He also links to 4 other tutorial pages on that main page I linked to.
I also have 2 small structure gen tutorials -- basics and complex structures.
Can't believe that I forgot about your two tutorials when they helped me fix my 81 variable issue. Added Both tutorials.
Please don't PM me to ask for help or to join your mod development team. Asking your question in a public thread preserves it for people who are having the same problem in the future. I'm not interested in developing mods with people.
http://courses.vswe.se/ the introductory java lessons specifically... not the outdated minecraft specific lessons... He includes questions and exercise plans which are useful for self testing and practice as well.