A Few Questions About Mint Cancelled Items

I've seen error coins cancelled with, what looks like, cuts from snips. Was this done at the mint? If so, what years did they do this?

Almost certainly NO.

In what year did the mint begin using machines to cancel items? If I remember correctly it was around 2004.

I believe that is the right time frame.

What is the oldest coin you've seen cancelled? I've had cancelled SBAs and I've seen coins back to 1976 that are mint cancelled.

I can't say I haven't tracked date, but I do seem to recall having seen some waffle canceled coins that were from before the mint started waffle cancelling them. How these items would come about I can't explain.

Do all US Mints cancel items?

I don't know, but probably. The reason for the cancelling is so they don't have to provide security for these no longer legal tender coins while they are being shipped to the scrapper. It would probably make more sense to have a waffle machine at each mint, that to provide security to ship them all the way across the country to Philadelphia to be waffled so they can be shipped without security.

Does the mint ever cancel copper planchets or cents?

Yes

Does the mint ever cancel silver items?

I don't know, but probably