Until Shona (from Here) replies I can tell you that Here Map Creator users don’t have access to change school zone data/locations. This change can only be done by the HERE employees. Please provide specific location for HERE. Exact coordinates are probably helpful in this case.
Re Speed Limits in your area. I randomly looked at 10 sections of roads in Bray Park, Qld (Brisbane) and in all cases I noted speed limit data within MapCretaor. To assist the HERE folk please provide specific road names & sections of roads so they can assist you further.
Re speed limits it is very unusual for there not to be speed limits set on urban roads & highways. But from my experience many small rural roads throughout Australia still need to have speed limit data attributed to them.
Hope this helps you a little.
BTW I’m not a HERE employee, just one of the experienced HERE contributors in Australia.