One way to tackle the issues could be by considering to become the committee, as your neighbour has done. In QLD, the body corporate cannot delegate its functions – only authorise people to do things. Thus, your body corporate manager (BCM) does not have the power to make decisions, they only should act on instructions from committee.
If you believe that there are others who contravene by-laws, you can take action as individual owner if the committee does not act after you have let them know. BCMs n QLD can be engaged for a max 3 years, so the chances are that you will be voting soon for a new BCM. You can obtain the quotes for a different BCM and submit them for consideration at the general meeting.
You can also require committee to vote on motions – up to 6 motions in a financial year – with legislation requiring a committee to act and respond to you. Living in strata is requires personal involvement, even if you pay BCM for administration. Committee members are volunteers, and in most cases do not get any honorariums for their time. They are, however, bound by their legislative duty to act in the best interest of all owners in all they do or not do, and they do have a Code of Conduct in legislation to abide by. Giving them any support (by, e.g. sourcing a quote from a contractor to help to speed up the repairs) is not unreasonable and provides for the shared workload.
There are also some changes just introduced to QLD Parliament regarding BCCM Act 1997, that includes issue of parking and ability of body corporate to tow that may help you deal with the issue of other owners parking unlawfully in visitors’ spaces. UOAQ is an association that supports QLD owners, check their website for more information.
Exercise your rights as an owner via conciliation process as soon as the issue arises and is not dealt with via self-resolution process. Conciliation does not require representation and the conciliator will be familiar with the BCCM legislation that will help to understand your issues within the framework of legislation.