1 & 2 => you'll need to be able to rely on your customer records being clean/not contain duplicates => can most likely do these as a search, use search and scheduled script and/or map reduce depending on size to update customer records 3 => depending on the info you'll need, probably a combo of N/query and N/file, then adding the buttons via a user event script/client script 4 => 🤷

This is brilliant, thank you. It's just really helpful when someone points you in the right direction. And yes... a couple of weeks...well I have a bit longer but I need to have something to show by then ideally.