Which leads me to ask.....In QLD, NT, SA..
Also in WA
Does it need to be written on the licence?
Not in WA, it's an unwritten rule. unfortunately it has lead to some confusion as many people think that this relates to ALL scooters.
Do they still wear 'L' and 'P' plates?
In WA there is also a R-N licence, which covers "mopeds" (ie 50cc scoots) ONLY. If a 17 year old, or an adult without a car licence, wishes to only (or can only) ride 50cc scooters then they can apply for this class, in which case they do need to follow the standard L, red P & green P plate system.
Are "go-faster" mods illegal for that class?
No it's not legal (in WA) but then it's common practice & I don't know of anyone who has been charged for it.
Do the riders have to undertake any courses like 'Stay Upright'?
If the rider doesn't have their car license & is going for the RN class then they are required to do the test. They won't pass without an escort & are far more likely to pass if that escort is a qualified instructor as the examiner can see that they've made some effort to learn the ropes & so are (hopefully) more likely to be safer riders.
People who ride scooters on their car license aren't required to attend lessons.