is it possible to use the drools editor etc in an eclipse RCP
If you only want the editor, you should probably try to extract that
the plugin and remove all other features. That should decrease the number
of required plugins (like for example the debug and gef plugins). Note
however that some of the features in the drl editor do require the jdt
plugin, as the code completion for the editor is based on the Java code
completion provided in the jdt plugin.