Keep him until you find a replacement, assuming you can afford to place him on the roster verse poor opponents and/or scrimmages within your current setup at PG.
He is not worth training long term, but a lot of people will take on folks behind in pops who have at least the OD and PA up to standards. Therefore, while your looking for a better player, why not maximize PA training and hope to get to 6 or so. I wouldn't bother short term on DR/HA unless you can only afford to two position train him.
He has 46 skill points (add all areas except stamina/ft), which is roughly what an 18 year old that you'd look to train would start as. It means he's roughly 13-14 pops behind. Add to that the fact that someone would eventually want to correct that FT prior to him capping, and you're looking probably until age 23 to get him to a D.III level. That is why i think most are suggesting that he is simply too low down to consider developing.