The photos are either too blown up(zoomed in) or your camera is extremely low resolution. You may consider cleaning the glass better or something, are you using macro mode to take these shots? You might get clearer photos using a flash. I find that I get much clearer photos with my lens jammed up against the glass. I used a point and shoot camera as well.
I'd clean your glass thoroughly. I carefully clean the inside of my glass, then wipe down the outside with some glass cleaner a few times before shooting my tanks. If you're not jamming the lens up against the glass, try that. It might be partially that your fish blend into the background as well. I have a heck of a time photographing my male Ps. Crabro when he's all black for breeding because the back of my tank's painted black and my sand is black. In almost all of the shots I can see stuff on the glass though, so I'd start there. Many of your shots aren't very compositionally sound either, things aren't taking up the right space, you have a huge amount of foreground then the fish and it looks awkward. I'm not sure how many photos these are out of, but I usually end up filling a 1 gig card then picking out 3-4 photos from it that I actually like. I'd try to frame the shots on a contrasting background as well.
My crabros look nicest against the substrate, so I try to shoot "down" at them, whereas my mainganos don't stand out nearly as much against the substrate as I'd like, so I try to make sure that rocks are in the background when I photograph them.
Even "bland" fish can appear interesting with the correct lighting and background, here's one of my mostly white/tan multies against a dark background
Try to accent the interesting colors that the fish DO have as well
The trick with good photographers is that they only show you their best shots.
How big is the lens on your camera, or what model is it? A camera with a larger lens lets in more light in a smaller amount of time, which is helpful when photographing fish because those buggers are so fast!
i know you were looking for information on quality of the pics but i noticed that in one of the pics of your Kenyi, she looks very fat or has bloat. Make sure you do not over feed. These fish will eat themselves to death
It's possible the fish is just a little deformed. I have a met. Callainos that has a WAY bigger belly than that guy and is coming up on a year in my tank. Other than the occasional digestive tract blockage, he's fine. But be sure that the big belly didn't appear recently.
I get flash glare in the vast majority of my photos. It's just a matter of working out what angle works for you. You may try putting a cone of paper or something around the lens to block it off from flash reflection. The lens on the camera is fairly small though and I think it might just be having trouble picking up light. Have you tried cleaning the glass on both sides?