You don’t want ${record.earliestdate} as it’s not a field that you’re accessing from the record – just use ${earliestDate} since it’s a variable you defined yourself. And to print it in the header, you need to put it in the part of the PDF code between <macro id=”nlheader”> and </macro> (should be near the top of the code).

It’s possible with SuiteScript, but not just through the add-on, no.

You probably want to first identify where the error is occurring – does it let you search the record and fails on “nlapiPrintRecord”, or does it get to there and fails on “nlapiSubmitFile”, etc. Once you know what specifically is failing, you can troubleshoot further – for example, if the searchRecord is what’s failing, you can try re-creating the search in the user interface to figure out what filter/column is breaking it.