there is a feature in CLCL that allows you to discard duplicate items when you do a copy. this is very useful because it keeps the Quick Paste menu neat and short.
Too many radio button options. I would just retain the newest duplicate and automatically delete the others. Why on earth would anyone want retain older historical duplicates in the first place? I would apply this feature only to items the Quick Paste folder.
I just believe simpler is beautiful. Too many features is a bad and confusing unless they can be folded into existing features well.