Yeah, I saw the mysterious screw. It looks like there's a sleeve inside. But then you've got the cost of a port and the bigger issue of who's going to warranty it. Olympus told me any modifications like that would void the warranty. I think a 3rd party housing may be a better answer for advanced users.
The 17mm Oly will vignette.
Turning the camera to spot focusing, it is quite quick to focus, much, much faster than a P&S, not quite as fast as a DSLR. I spun it around at the show and it locked very quickly. A good focus light will improve things, but I tried focusing on a crack in the dark wood floor in the shadows and had no problem. The 9-18 is faster, due to internal focus.
James, not sure abotu the EVF.
I'm promised a demo unit to do some test dives with the system. But it'll probably be a month.
Jack