I must have been watching different games than many of the posters here.
Because to me RJ looks like a guy who knows the game of basketball. His defense, awareness, passing, and especially his athleticism were all better than I expected. He can handle the ball without turning it over, his passing is crisp and innovative, he reads rebounds pretty well, his defensive positioning is decent (not perfect, but not bad, considering rookies usually embarrass themselves), and he generally looks like he knows what he's doing. For a rookie he was fairly poised and well-rounded.
To give up on him so early would be stupid. Most rookies are completely awful. Remember Bradley in his first year? It's hard getting dumped into this league, having to learn new sets with new teammates, against incredible competition, all with expectations that you'll come out firing on all cylinders despite spotty minutes - and in this case the C's logjam at guard certainly didn't help Hunter find his rhythm. And still IMO RJ looked better than most.
I think the tools are there. Ultimately his shot falling will determine if he'll be a solid NBA player or not. Unfortunately they weren't last year, and so as a shooting guard that makes things look a lot worse than they might eventually be. But the IQ and work ethic are there, and his issues can be fixed. There is enough skill, IQ, length, and athleticism there to be optimistic.