Hey Darryl - congrats on putting together a nice rig! And it looks like you had some great dives in Palau.
I feel kind of uneasy making comments critiquing your photos, as I just put a new Canon 20D to work only a week and a half ago - my first experience with a DSLR. As long as everyone realizes that I realize that this is likely a case of the blind leading the blind, here goes.
My favorite shot was the apparently natural light shot with the free diver and jellies - great composition and a good exposure. It seems like in some of your closer-up shots that there was't a lot of light from the strobe reaching the subjects, so to me they looked like they lacked warmth. I know you've got just a single strobe - like I do - so I'm sure it's hard to get sufficient illumination sometimes. Here's a link to my first batch of 20D photos - they're all 60mm macro shots:
20D 60mm macro shots
I was pleased with the overall warmth in most of these shots.
Maybe in your case there is something that can be done on the image processing side too. I do sometimes adjust the EV values in my .RAW images before working on them a bit in Photoshop, where I sometimes tweak the brightness histogram. In this regard there are a lot of really smart & experienced people out there who should be able to give you some good guidance.
In any case - best wishes on your trip to Bonaire!