Re: aluminum wiring
I believe the "white black exception" you are referring to is the use of a white wire as a hot in a switch loop, it is not limited to aluminum wiring. Did you check the fixture you bought to make sure it was AL/CU rated? Did you use an anti oxidant? When dealing with aluminum wiring it is always best to have someone that knows what they are doing or you could end up burning down your house. I believe you are over your head, please call a professional.
Be sure you live your life, because you are a long time dead.-Scottish Proverb