Hi Prathamesh,
Issue1: if actionPackage is not predefined in combobox you're free to edit it there because combobox is NOT read-only
Issue2: there are predefined varibales {class-name},{package-name},{build.dir},{destdir}. Please see some examples in doc (http://docs.jboss.org/tools/)
Issue3: I'm not sure if there is any really comprehensive book for hibernate tools, some things are refered for example in JBoss Tools 3 Developers Guide but it's not probably as detailed as you need
-- Jirka