you should seriously try an alternative shell nobody uses. like zsh. it doesn't beep at you when you tell it to stfu, doesn't force you to painfully wade through filelists (every tab cycles through the list of matching files; is the output more than a screen full, you can scroll through all matches and even use the arrowkeys to select one. this can be a bit awkward to use unfortunately...) and even takes typos into account when completing. i hardly used any other shells but i find zsh's completion system to be utterly superior, though you have to meddle with the config a bit to get the desired effects. it comes with a sort-of setupscript for the completion system.

regarding default actions, why not assign a single letter a function or script? like:

function d {
 case $1 in 
  *.jpg) bla $1;;
  ...
 esac
}

shouldn't be too much typing overhead.