Yes, the Winter Soldier comic is considered canon within the Marvel Comics universe. It plays an important role in shaping the character's story and continuity.
The Winter Soldier's age in the comic varies depending on the specific storyline and continuity. But typically, he's depicted as being in his 30s or 40s.
A common theme is redemption. Bucky's past as the Winter Soldier is often explored, and the OC plays a role in his journey towards redemption. For example, in many stories, the OC helps him face his past actions and find a way to move forward.