The ¥2,100 round trip is worth it when the summit is clear. The ropeway can run normally while cloud hides the city, so visibility, not operation, is the question.
English Mass is normally 12:30 on Sunday at Catholic Kitaichijo Church. Check the dated monthly schedule first: some Sundays become a Communion service instead.
Worth the detour if the factory line and sweets are the draw, not just the famous souvenir name. Add the garden or a DREAM KITCHEN session and it passes two hours.
You do not need Namba. If the Kansai-Airport Rapid lists Fukushima, get off there, one stop before Osaka Station, and walk ten minutes south to the museum.