Production of driving documents

• I have got a fixed penalty notice. Do I have to surrender both parts of my licence?
• I have got to produce my documents but I am away on holiday/ on business and do not have the documents, what should I do?
• I have received an endorsable fixed penalty ticket and need to send my licence off but I am going on holiday and need my licence. What can I do?
• I received a citation/conditional offer for a traffic offence through the post and have since lost the document. What do I do?
• Is it an offence not to carry all relevant documents when driving so they can be produced for a police officer upon request?