>>> Did you just epoxy the mount on the housing?
Yes - I used quick-drying, steel-reinforced epoxy. It worked great in normal diving temperatures. When I took the camera out in the case on an extremely cold day this winter, not surprisingly, it fell right off. I'll redo it for the upcoming trip and will use longer-drying epoxy that I will reinforce with some sort of fiber like twine or something.
>>> The cheap focus light intrigues me.
$45 ... can't beat that. I have heard complaints that it floods, but I dove with mine every day for a week with no problems.
>>> Does it light up macro stuff well with the camera on its smallest aperture?
I'm not sure how aperture comes into play ... can you explain?
It certainly lights up macro stuff well and allowed me to have perfect focus on my night dives. The mount allowed me to shine it directly down on stuff right at the front of the port. During the day, it helped a lot at depths over 50 feet when the camera was hunting a bit without it and obviously under ledges and whatnot.
What's really cool is the automatic strobe sensor ... when they fire, the Nano light shuts off so as not to leave a hot spot on the captured image.