Good questions. To the first one, did you do an apt-get update before trying to install Totem? (By the way, there are still problems with getting sound off of Easy Debian apps.) After you do an apt-get update you can see all applications available using the dpkg -l command. That will give you a long list of available apps. If you are searching sor something in particular, say totem, do this:

dpkg -l |grep totem

That sends the resulting list to the grep command that filters out every line not containing the word totem.

As far as the second question, I am not sure. It may be that the Install Image command does something special in order to set it up.