[Gnawrocki1]

Glen sounds like you went the extra mile I might follow your lead on the epoxying the rivnuts. Did you use 5/16"? 

I did use 5/16 aluminum rivnuts to prevent any galvanic corrosion.  I did not want the nut too big as I put them through the roof supporting aluminum L cross section that was not very wide.  
I read somewhere that sometimes the rivnuts will spin on aluminum and the epoxy should help stop that as well as seal around the top of the nut.

I used stainless bolts to hold down my unistrut and added a dab of some zinc compound that should reduce any galvanic corrosion at the nut interface......but it should not be getting wet anyway.