1) I am trying to use your conversion program. I can see the preferences and the fact that I have registered, but all there is when I open a jpeg picture is a large square with some indication in small print that it did something, but with no picture and a smaller square with nothing in it. Any ideas?

Let analize some steps.

a) Are You using mac osx or 9.xx?
b) Verify the about box.
it should appear similar to the following picture:

You can also send me back the capture (command shift 4)

And the program should appear like this:

Now verify the prefs.
In prefs You can change a LOT of parameters:

In this example we:

a) FORCE resolution ( the quality is the same..) to 300 dpi
b) ADD and underscore before the name to get a different file, leaving the original untouched. You can also add a suffix, for example to pass from standard Picture omn mac to JPEG adding JPG for PCs.
c) ADD in center an orange , red-bordered text, "Hello world" in Charcoal.
d) SHOW preview in right windows. Note: using preview, conversion speed goes down.

so let's open and convert the file, of my last trip to maldives.....

simply dragging over the left window:

If You enable preview in prefs, You will see the converted imaged on the right.
You can also choose "Open.." as usual.
You should see:

With the left some infos on file type and conversion, on the right the preview.
and on disk:

NOTE the fle type is changed, as we NOT forced to special type.