Is there any regulation regarding selling and buying of water, fire (energy) or land? Some say that there is a hadith that forbids this kind of transactions. Is this true?
These properties are natural resources. Normally, they belong to public authority. If the public authority privatizes, then there is no harm in buying/selling these properties. But if there is no privatization and/or regulation, one cannot simply lay claims to natural resources without public consent. The hadith you told about was about misappropriating these natural resources and selling them like they are a privately owned property.