1995 Timing Chain

Hi Everybody,
I have a '95 Maxima Engine Model # VQ30DE that has 202,000 miles. I have been informed by my "mechanic" that the rattle noise I hear in my engine compartment, especially when the car is cold, is my timing chain. Of course he recomends replacing it at a $1,000 dollors in labor just to get to it. Any suggestions, recommendations or ways to comfirm that it is indeed the timing chain would be greatly appreciated.

Could it be just the tensioner and if so, is that as labor intensive as replacing the actual chain(s)?

If this expensive deed does need to be done, what else besides the chain(s) and water pump should I have replaced as long as they are in there that far?

Thank you in advance for any suggestions on this matter

Sincerely,
Mechanically Uninclined