Not really a restaurant, it's actually the school tuck shop. They have a policy of providing good meals and they're open to the public. It's all take-away and not sit in, but you can always find a shady spot nearby in the grounds.
Outside of the immediate family and close associates, Aborigines are very private and reserved. What may appear as politeness and friendliness in a European environment would come over as rather rude and offensive. Although, depending on the individual, some Aborigines are already used to the 'indelicate' behaviour of non-Aborigines.
Better to be hesitant rather than forward. Don't approach people from behind. Let them know well in advance you're approaching. A loud cough is quite appropriate.
Roads throughout Arnhem Land, apart from within some communities, are all unsealed and the conditions vary from reasonable, well graded, to extremely rough 4WD only. The most dangerous parts are the straight well graded sections because people tend to speed up and then get into trouble at high speed. If you have a serious accident it could be a long time before another vehicle comes along, let alone the time it would take for any emergency service to reach you. Mobile phones don't work out here.
Arnhem Land travel can be exciting in many different ways. But you're often a long way from help. They say it's "God's own country" so it's not surprising that it's also a case of "God helps those who help themselves". There's no one else around to help. The wise come well prepared and well equiped.