Hi Carl
For the Scorpionfish the strobe (left one I think) was directly over the camera. The fish was lying inside of the sponge so it was the only way to light it. I was way too close to the subject for side lighting to be effective. Most of my macro stuff is taken using one strobe , typically above the camera unless the position of the subject dictates otherwise. For really small stuff I will point the strobe directly at the subject, othewise I will aim it parallel to the lens to use just the edge of the strobe. It is sometimes necessary to use both strobes for macro, especially if there is coral or other marine life / objects preventing decent lighting. It's a judgement call I make when I see something I want to photograph. I will also review the image on the LCD, if it doesn't look right I will re-position the strobe/s and try again.
I use the dome with an Oly WCON-07C wide angle lens. In fact the Scorpion pic was taken with the WA and dome. Shooting through a flat port slightly narrows the field of view of the lens owing to refraction, the dome corrects this.
Thanks for the kind comments and interest !!! If I haven't answered everything please ask, I'm only too happy to help.