Thanks for the feedback. Nice to hear that we have some EDM users! I am one myself, and we wanted to make this software usable for many different genres.
We designed the import audio file workflow based on that users listen to their samples in Finder on Mac (or Explorer in Windows), and then import it. Although - it's not a bad idea to have a preview in the import dialog. We'll look into that...
Having more options in the Search for Instrument, like importing and tagging custom sample audio files is also a thing we have explored but not yet implemented. We'll continue to investigate that area too...
We can't, however, say when or if these things will end up in SD3...