Will 6'8" height make training outside skills difficult?
According to the Parrot, compared to a 6'0 player, your 6'8 trainee will train JS at the same speed, but JR, OD and HA will only train at 66.7% of the speed, while DR and PA will still train at 83.3% of the speed.
At the same time, your 6'8 trainee will train 79.5% faster (or at 179.5% of the speed) than a 6'0 player for IS, ID, RB and SB (but only at 72.9% of the speed of a 7'4 player).
"Air is beautiful, yet you cannot see it. It's soft, yet you cannot touch it. Air is a little like my brain." - Jean-Claude Van Damme