When I get silvers, I get dupes a lot, but I don't buy those. Haven't got a gold dupe yet and will be very annoyed if/when I do. I personally have found no use for Sebastian's, Goofy's, or Minnie's abilities, as none of them really benefit me much. Nemo and Hopps so far have been the best ones for score and coins for me.
Also, I've never had the wiped collection progress thing happen, thankfully.
And moonsugar, I dunno why your emojis aren't showing up on the keyboard, I have no trouble finding mine.