As a person almost solely interested in metaphysical studies, what do you recommend I major in in college?

Yes, definitely philosophy with a minor in religious studies…or the other way around. If you’re also interested in developing good critical thinking skills, use of logic, philosophy would be the choice. Are you thinking about divinity school, or is it just an interest. I hope you’re aware that with such a liberal arts degree, it’s not easy to get any paying job with that interest. Keep that in mind as you read through your online or paper undergrad catalog. But it’s your ultimate decision, so best wishes.

Edit: Just to clarify–Let me add that if you’re yourself very much interested in religion, then religious studies would be just great. But, if you’re more interested in the theoretical aspects of metaphysics, then definitely choose philosophy as major over religious studies.