The idea of creating an IDE for ADMB is great. The currently one, which is based on Emacs, works well out-of-the-box. For a new Emacs user, it is great - the IDE has been tweaked in the way people who are not used to Emacs key binding can use immediately. But for people who use Emacs on daily basis, and have a long .emacs file, the idea of making heavy changes on the Emacs configuration file (key bindings, etc.) might not be that attractive.
A better solution will be to offer three different sets of configuration files: the one is for completely Emacs newcomers, the second one is for people who have some familiarity with Emacs but are willing to make some changes to their work habit, the third is for those diehard Emacs user who only want a syntax highlighting and maybe a key binding for compiling a .tpl file.
Well, it turns out that the "minimal IDE" I was talking about is already there: the ADMB Emacs editing mode. Simply put this file in the include directory and put two lines in the .emacs file, it works like charm. All other customizations are entirely optional. This seems to be a perfect solution.