Is the aforementioned method, which consists of writing Surat Ar-Rahman with saffron and washing with it, reciting the entirety of Surat Al-Baqarah with a specific supplication, and reciting Surat Ya-Sin daily, correct for dispelling magic and facilitating marriage?

The method mentioned has no basis in Islamic law for curing magic or facilitating marriage; it is an innovation. Magic is cured by what has been reported from the Prophet (peace be upon him) and his companions. As for facilitating marriage, it is achieved through obedience to Allah and steadfastness in His religion, for that eases affairs and removes obstacles, as in the Almighty's saying: "And whoever fears Allah - He will make for him a way out and will provide for him from where he does not expect" and His saying: "Whoever does righteousness, whether male or female, while he is a believer - We will surely cause him to live a good life." Among the beneficial causes are also frequent supplication (du'a) and seeking forgiveness (istighfar), for Allah Almighty says: "And said, 'Ask forgiveness of your Lord. Indeed, He is ever Forgiving. He will send [rain from] the heaven upon you in [copious] showers And give you increase in wealth and children and provide for you gardens and provide for you rivers.'" And for the Prophet's saying (peace be upon him): "Whoever adheres to seeking forgiveness, Allah will make for him a way out of every difficulty, and relief from every worry, and will provide for him from where he does not expect."