You can apply for a 10 year CPL if you want instead of 5. Most people don't as it costs more and they hope that they will have a full ATPL before the five years are out.
AFAIK there are no requirements for keeping your CPL 'current' other than paying the fee and filling out the form to get it re-issued. As Go-around rightly says, the things that need to be kept current are the ratings that give you the aircraft priviledges, e.g the SEP / MEP etc.