Comet to Lleystad - Current policy is not to send the aircraft overseas as an engine failure over water could lead to total loss of (pilot as well as) aircraft. However, nothing is set in concrete. Risk to the aircraft and hours burnt off must be weighed against the event it would be attending and remuneration. A trip to Lleystad is unlikely, but always possible.
Wroughton - perhaps, but same criteria wrt risk, hours, the event and costs applies.
Air race event in 2005, or when the Comet is back in the air - I expect it will be high on the agenda, but you'll have to wait and see as to exactly when.