I appreciate your feelings towards the roads. Alli can say is that getting stronger at riding can really only be done by riding and the hills will be your friend. Ride the hills to avoid the cars. I also don't really like riding the main roads especially in the weekdays but more cyclists means more awareness and groups like the Bicycle Institute, SA work to lobby government etc to make a better cycling environment. A strong community helps as well!... And some good friends.
Adelaide BUG (Bicycle User Group) is an online group with an emphasis on advocating for better cycling conditions. You can become a member via an AC web page. Currently 66 members. Learn what is happening in the CBD cycling wise, post about your own concerns, or report a pothole.
Another new AC member said he would be interested in rides. My response was that he could organise an occasional ride, or a meet up for coffee, especially during lunchtime for city commuters. Perhaps when the weather is sunnier we could organise a cycling tour of historic sites or buildings, or a byo picnic in the parklands. I have added the suggestions to the Adelaide BUG intro.