I just fixed some bugs in the after_install and before_uninstall callbacks. New version is
here.
And yes, it currently only supports oracle since i don't have a single clue about postgres. But I hope that the postgres port will be done soon.
Regarding removing internationalization: yes, you could remove the code but it would probably be easier to add a ad_lang table and substitute every [ad_conn locale] to some default value and remove the possibility to change the locale in cadmin/master. In that way you would be compatible with the 4.7 version.