Blue Water...nice of you to put general directions on your site.
A couple of comments on those directions (which in general are reasonable).
1. I stopped doing manual exposure with a point and shoot several years ago. They have gotten so good with flash TTL, that I typically go dozens of dives without a bad exposure. (assuming the system is setup correctly). With the listed camera's, using manual requires manual strobe control, so one has to use some other setting, either presetup or use shutter priority (I cannot think of a single time where DOF was an issue with these tiny lens.. but it could happen I guess)
Note: Given the really fast lens on this camera, the above may not be a good suggestion, as it would depend on what it defaults to. With the G series, it is a non issue... even the S does not pick wide open.. If it went wide open, would go the manual amount unless one of the theme setups corrected that (those things I never use)
2. Be careful using the lowest flash setting in bright conditions, several of my flashes will not trigger (depending on the housing and just how bright)...
3. Most point and shoot's have greater magnification, the wider the lens setting, but you loose working distance. And lighting an object pressed against the glass is, well really difficult.. so your zoom out is a great suggestion. But be careful...some are not uniform. The LX-5, for example is at it's worse when zoomed out in the middle of the range...all the way is actually better, and wide angle is the best (very odd actually and was surprised by that. I don't know what the Oly is, but one should check (the S and G series are standard).
4. Focus setting... well actually the whole issue of picking the right setup for underwater is one of the most common problem I see with these cameras. If you leave the default setting in place, and you want to take a fish picture with something behind it, the stuff behind will be in focus. And to make things worse, contrast detection systems don't work on a lot of stuff. I strongly suggest that people use spot focus, and set the spot size to what they like taking pictures of... as well as learn to prefocus the camera on something the same distance to get infocus images of those hard to focus things...like dart fish, jellies, etc, etc.
