Wow and you say their tech support is poor. Ok on the dome light look at your headlight diagram the dome return is the ground wire for the circuit and is used for swithing on and off. For power to the dome lights you could tap into (headlight power = red/black) thats the same circuit as originally wired by GM. Fusible link I would not run it to the starter instead run it as I stated before but check out this site first there is loads of usefull info there and you would better understand the charging systems pros and cons, the tech articles are all very good reading.
http://www.madelectrical.com/electri...1.shtml:metal: