Was Okonkwo violent and stubborn

No, in the sense that it is being used. While it is true that Okonkwo was ignorant of colonialist customs and traditions before they came, the same could be said about the District Commissioner about the Igbo tribes and customs. The entire book of Things Falls Apart shows a deep complicated culture, with a full judicial system, social norms, stories, proverbs, songs, and ritual.

Okonkwo is only ignorant in the sense that everyone is ignorant, and a native by the fact that he had not emigrated to another country.