Greetings & Salutations Steve!!!
I've found S100 Cycle Cleaner to work best out of variety of products I've tried. Follow instructions on bottle (spray on, hose off). Amazing how grime just flows right off.
Wiring connectors are exposed with no weather-proofing seals, so water can be concern. Most of them have rubber hood over connector. But don't worry about it if you dry out connectors afterwards with hairdryer. Won't be 1st time that bike's been wet.
Someone posted recently on using old cut-up license-plates to fill in hole in fairing for turn-signals. I've used CF and Bondo to fill that hole. Then you can use any aftermarket stalk or flush-mount signals you want.