I do like the new series I just think introducing the Helen being engaged to the posh bloke story was unnecessary. The original was just a sweet, romantic but down to Earth boy-meets-girl story, falling for each other as they washed up in the Village Hall. They deliberately introduced a false jeopardy because we all know he'll end up with her.
As regards Tristan, I think he did work at the surgery before he was completely qualified in the books, presumably nominally under supervision.