As Johny said stamina is very important. It helps your playesr play at high consistency throughout the whole match. If a player has low stamina, he will get tired towards the ending of a game and perform much worse than normal.
As for FT, I don't see them play an important role. I mean, I have players with low and high FT skills and they shoot at about the same percentage. It usually only makes difference in a big sample of FTs attempts.