My latest drawn up suggestion is based on the KISS principle and working within current limitations of the go card software
(if there are suggestions that won't work within the current cubic system limitations, feel free to point it out)

Go Card Structure
- All paper tickets scrapped
- Increase vendors outside major bus stops and unattended train stations to sell concession go cards.
- All go-card machines at railway stations to be reprogrammed to sell adult go cards.
- Preloaded go-cards on all buses - $10 for all operators including BT ($5 deposit and $5 preloaded credit).
Fare Structure
- 3 journey cap per day (replaces the flawed 9 and free weekly pass)
- Concessions extended to all Health Care Holders with Newstart customers getting a dedicated HCC/Go Card combined card.
- Combined HCC/Newstart go card allows Centrelink to track attendance records. Continual no attendances without valid reason, the card automatically switches to a full adult go card.
- All users pay the same fare during off-peak & weekends. Concession holders pay 50% of the adult peak fare during peak times.
- Children aged 5 and under travel free with a full-paying adult (go-card should be registered to allow this).
- Up to 2 Children - aged between 6 and 12, travel free after 6pm and all weekends with a full-paying adult (Allow the linking of the child go card(s) to the nominated adult).
- Peak period is between 6:00am* and 8:30am and between 3:30pm and 6:00pm. Based on touch-on, thus touch-ons before 6am* allows off-peak discount (and also allows early-morning passengers on the first 3 inbound trains from Varsity Lakes, and first 2 inbound trains from Nambour to utilise this discount).
*5:45am touch on cut-off for stations south of Beenleigh and north of Caboolture.