Conversion therapy is not going to work because the cause of sexual orientation is probably biological. From https://scienceinsights.org/is-being-gay-genetic-what-science-actually-says/
Sexual orientation is a complex trait resulting from an intricate interplay of influences, not a single cause. Current scientific consensus points to a combination of genetic, hormonal, and developmental factors interacting during an individual’s formation. It is likely shaped by multiple biological predispositions that manifest during development.
No, Iran reaching an agreement with Europe would show what type of deal Iran is willing to accept. If most countries like it, the US might follow. Also, Europe would immediately begin trading with Iran.