hey there,
I just wanted to give an update to this issue. As stated earlier in this thread, I more or less accidentally bought one of these players that never made a free throw in 5 or 6 seasons. I gave this player one week of free throw training. As to be expected the sub was low that there was no skill up at this player.
but since then the player did not made such a large amount of free throws as to make a solid statement, but there is quite a hint that this only training brought him up to around at least 20% (league games 1/4, cup 3/8).
cheers