Can you disagree with Les Feldick's teachings on Scripture and still be saved?
Yes. A person can disagree with some approaches to Scripture and still be a believer; such disagreement does not put one in danger of hellfire. Salvation is not conditioned on agreeing with every teaching approach, but on being a believer.
Les explains that the program is an informal Bible study, not denominationally connected and not underwritten. He notes that the audience may include various denominations, and his purpose is to get people to study their own Bible. He directly says listeners may not always agree with him and do not have to; they can disagree with some of his approaches to Scripture and still be a believer, and still not be in danger of hellfire. He passes on what became thrilling to him, especially God's dealing with Israel and then His turn to the Gentiles, which he presents as a whole different approach. Once a person sees that, the book becomes exciting and easy to comprehend. He also states they do not attempt to profit, and the Lord has supplied their needs.