Is writing Surat Al-Fajr with rainwater and saffron, then anointing oneself with it while listening to Surat Al-Baqarah to facilitate marriage considered magic or innovation, or does it fall under the category of legitimate Ruqyah?

The act mentioned is not from the guidance of the Salaf, but rather from the ways of sorcerers. It is not permissible to believe in its benefit or its facilitation of marriage, due to the lack of knowledge of its benefit through Sharia (definition) or experience. It is polytheism to rely on a means that Allah has not permitted, neither by Sharia nor by sensory perception. You should seek assistance through patience, prayer, and supplication during times of responsiveness. You can recite any surah (definition) from the Qur'an and supplicate with it. However, specifying verses or surahs with virtues or for fulfilling needs without evidence is an innovation.