The guy originally was Kingcustomcycles he was a guest dude that would comment here. If you dig thru searches here he comes up sometimes
Originally it was sold but the reason it is hosted on the site was because he decided to post it up as a resource for us for free. It was actually a cool gesture.
The diagram has some flaws but IMO, and wouldn't work for some, is a good enough guide to just work something up with. I have a good understanding of electrical systems and the fact that you are working with a bike, hacked up or not helps, it is not truly from scratch with no identification or clues
The 30 amp is overkill, as a 15 amp regulates all then eventually thru the 7.5 and 5 amp but when you are talking shorts, which are like infinity it is gonna blow almost any fuse, up to some MAXXI type that is like 150amp. Probably blow that too, you never know. The oversized fuse isn't really gonna matter much
I didn't find it too useful, I did my own thing with relays and such but I have a tendency to freeball most projects anyway. I personally think oldmanhonda.com and the like, with stock diagrams are more useful. add/subtract tweak existing to your style/needs