As far as I know the only lateral entry available at UNSW is from the UNSW BMedSci course. At the end of 2nd year you are granted entry, subject to completing Hons in BMedSci. You then move into 4th year of the med program. ie 7 years total.I suspect your scores will be too low for UNSW, but I'm not sure if lateral entry is more forgiving, so that might be your only hope. With regard to the UNSW application, the very (very) short answers are not used at all to score your application/invite you for interview. They are only used to guide questioning if/when you do get an interview. In other words, don't panic about them too much, but write something you'd be prepared to talk about if you did get an interview.
I know of a person who was successful in this transition. At the end of 2nd year when she was accepted, she had straight HDs.