I want to be flexible even after deploying my code so I like to use the hibernate.cfg.xml file for configuring NHibernate. Now, I am planning to use Fluent NHibernate to do all my Class => Table mapping. Is there a way I could use the old NHibernate Configuration class to configure Fluent NHibernate?
Yes, if you're using the fluent configuration API the Configure method has an overload that takes an existing NHibernate Configuration instance, which can be built from your hibernate.cfg.xml.