The plan to get to 10/10 IS/ID is solid. After that, he could definitely use a bump in both PA and RB. Maybe try to get those both up to 8+? After that, I'd say he would look pretty good for U21 and you'd probably want to do some rounding out. Add in some DR, pump up both OD and ID a bit, maybe another point or two in JS and some more PA... It's mostly just giving your guy a skill set that fits into your team concept at that point.