i agree. you should be able to get better pics from this camera. I have a earlier model of this canon. The 2nd photo looks good. 3rd photo looks like the focus is on the glass
ok lets try some things.
First, put it on the highest resolution it can be at at (large)
try the macro setting on the camera as well for shooting corals
keep the lens on the same plan as the glass, so as not to get that distorted view
if you have a tripod, use it. it will keep everything steady. if not, try putting the lens on the glass, so this will hold it steady.
the trick is to try everything and see what works. try these and lets see if you have any change.