seahorsedreams;
Your color looks really good in the above photos! We will be spending some time going over color balance techniques in a couple of weeks. For the most part the color balance instructions that come with your camera and it's pre-programed color settings, just don't work when shooting subjects through glass/acrylic, colored water lit by a bewildering array of color temperature light bulbs/fixtures. There are a few things we'll go over that'll help.
It sucks to hear about all the focus problems you've been having with your different cameras. Looking at the photos here, I see that you tend to have your lens's aperture very wide (2.8, 2.8, 2.8, 3.5, 5.6, 2.8, 2.8 & 2.8 respectively) which innately leads to a narrow depth-of-field (DOF) or a very narrow of acceptable focus. The closer you get to your subject (macro), the narrower your DOF gets for any given aperture setting.
Shooting subjects as close as you are in the photos above, I'd say try apertures of f8 or smaller and see what you think. You'll still have those nice blurred backgrounds but a little more of your photo's subject will be in focus.
Yes, that means you'll have to increase your ISO, slow your shutter speed or increase the amount of light hitting your subject (or a combination of them) to compensate for less light coming through your lens.
f1.4 & 1.8 lenses are great for low light and fast action, but you need to keep in mind that the DOF is going to suck at those wide open apertures, especially when you get up close to your subject.
You may well already know all of this, but I thought I'd mention it as some of it might help and it's useful information for all your classmates.
Cheers, Chris