Rattle could be chain with the mileage, especially if it's worse for a few seconds on start up.

It seems like quite an involved job I wouldn't fancy tackling it myself and would want someone competent doing it.

Regarding the age, mine's on 120,000 miles and is still going strong. They seem to be good solid cars if looked after and oil level kept on top of. A few little niggles can easy be sorted, lots of parts available. Plenty of people know their way around the engines etc too.