I think Dr. Selar would have been a better junior medical assistant than Nurse Ogawa. However, I'm sure the show didn't need the cold logic of a pure Vulcan. T'Pol turned out to be a total mess.
With the benefit of hindsight, Suzie Plakson's history in sitcoms points to comedic acting for her. Perhaps then I could accept a producer rejection of McFadden's suggestion, making Crusher more serious than she was but without turning her into a total character turn-off.
I am going to have to disagree somewhat. I haven't read Peter David's series with Selar in it but from the episode she was in,she by no means showed signs that she was your typical Vulcan. She wasn't cold, in fact she was rather pleasent though slightly sarcastic at times.