Personally I think I'd sell him. At 19, 60 tsp would be the minimum for me (I prefer higher still), especially with his potential, as its wasted if you don't get at least close to the cap. I aslo think his IS and ID, which in my mind are essential for every position, no matter what league level, are far too low to ever be able to do anything about. His outside skills are good for a potential PG but I have found even PGs with high passing and low shooting will still try to score more than you'd like and usually miss.
Is it possible for me to play a zone defense to negate the poor ID and just raise the OD to enormous levels?
It is possible. I did it in D2 with my main team quite a long time ago. I seem to recall I needed the most expensive team in the league to promote and usually now pay a lot less in salaries.