For what its worth, I think you should try to pronounce the dialect words correctly but not try overly hard to 'put on' the dialect. Otherwise stick to the English translation. I get very irritated by singers performing a dialect song with words from the wrong dialect - Scots or Geordie in a Yorkshire song for example.

I also get irritated by the preponderance of fake US accents in Country singers in Australia - isn't their own distinctive variety of the English language good enough for them any more?