There are wiring diagrams in the "Moped Repair" section of this site. I doubt there is a whole lot of difference between the 1999 wiring harness and the more recent ones.
I don't think turn signals are annoying to most riders. They provide added visibility and credibility. If you've already got them, I don't understand why you'd be "doing away" with them, especially if you're planning on selling the bike, anyway.
The headlight, on the other hand, could probably stand replacing. If it's anything like the one on my 2004 bikes, it's useless.
...Operating with impunity in the legal gray area between bicycles and motorcycles....