This might be easier if one could directly specify the interpreter to be used (like /usr/bin/ruby instead of sh) for a given script/scriptlet, in the manner of Xcode's shell script build phases.
Made a *quick* mock up on this, the small textarea, is insufficient for some commands, so how about using the editor itself to write it! Question is then, Should the script be stored in a standalone file, or the plist like today.
hp.