1 So "saved" is related to conversion but not salvation?
Please do take a minute to explain the distinction.
2Paul's words there in 1 Corinthians aren't talking about a person working on himself. Paul is talking about evangelism. Paul laid the foundation for this church by preaching Christ; Apollos is building on that foundation by continuing to teach. Paul seems to be saying that even if the church that Apollos is teaching is destroyed by the fire--if this Corinthian church doesn't withstand--Apollos himself will still be saved.
1 The act of Salvation, being saved is an act performed by Jesus when you ask him to save you. Ephesians 2:8+9 Done and done. Conversion is the ongoing walk in those which G-d has before ordained that you should walk in them. Ephesians 2:10
2 You are correct that Paul was specifically speaking of Soul-Winning AND discipleship. There is a need to transfer principles. If building on the foundation is discipleship and you are a disciple it stands to reason that building on the foundation in your life is a part of that.
Who is most responsible for your own discipleship? You are.
when your works are tried at the Judgment Seat of Christ G-d's works that you walked in will be rewarded and those works of the flesh will be burned up. So the goal of every Saved person should be to waste as little of their life on their own ends and as much as possible on the works that G-d has prepared for him.