I don't believe that this sleazeball version of Ralph is faithful to either the classic Plastic Man or Elongated Man. But it is the way modern writers tend to use Plas.
I can see why THE FLASH needs this kind of comic relief, right now. They don't have H.R. to kick around anymore. There is a kind of dry humour between Harry and Cisco; Grant Gustin can always do some really funny bits when the script allows it; but they need the reliable Pliable Policeman for the broad comedy. I get that.
I do hope that Sue Dearbon will come along and straighten Ralph out--get him to give up his hound dog ways. But I doubt that she'll appear this season. Maybe in season 5, if Elongated Man stays around that long.
Is it too out there to wish for a Snake Eye and Ralph eyeball fight?