Hi Mike. One thing you might try immediately is using proxies while editing. This will give you low-resolution files to work with on the time line, then convert them back to full resolution for rendering. GoPro Studio should provide you the tools to do this. I don't use Adobe, but Sony Vegas, which I use, allow for the creation of proxies when new source material is imported and I imagine Adobe must do the same.
If that doesn't help you might consider a computer with a bit more "umph"
