I am not sure you will get a lot of responses on this thread. FWIW, it is my opinion that the 14-45 is a slightly superior lens than the 14-42 but for underwater use, the differences would be minimal. Either is okay as a general purpose lens, and you can do decent macro with either lens and an adapter and close up lens, but neither is ideal for macro or wide angle. I would suggest deciding which you think is of more appeal (wide angle shots, including close focus wide angle, or macro shots of small things. If the former, look at getting a 7-14, 9-18 or 12mm lens, or my favorite, the 8mm fisheye. If macro, then get the 45 or 60mm macro lenses available for your system. If money is tight, you can do decent macro with what you have now, so I would look at a wide angle lens (unless wide angle is just not your interest. You will need to add a strobe fairly soon as well, although you can do a fair bit of natural light wide angle.
I would make this suggestion, though: Wait until you have been diving for awhile before dealing with the photography. Carrying a camera around complicates buoyancy and task loading at a time when you need to be focusing on diving skills. When you are feeling quite comfortable with your diving skills, then add a camera into the mix. For some this happens fairly fast; for some it takes awhile.
Now a shameless plug: I have a housing and ports for the GF-1 for sale in the classifieds and would be happy to make you a good deal on some or all of what I am selling.