His highlights package is impressive which is what most of us are going on. Keep in mind Sheehan is on the record saying the best highlights package he has ever seen is Raphael Clarke. Or was it Xavier? I can't remember it was one of them. Ben Nasons highlight package was also pretty amazing. Point is its not a great measure of whether players will make it.
All that aside, yes, he looks like he can play but jeez I hope he's not another David Burke who cant put on weight. And if he does, will he lose his leg speed?
If at 18 you are at least 15 kg off afl playing weight it raises the question of not ideal genetics for the game/laziness in the gym