1) Those tours are made by tour guides and we don't own that content and nor do we have ownership rights. Most of the revenue goes to content creator and we only take small fee.
If these tours are real experiences with a real person then see the answer to number 2 below. If these tours are digital content consumed inside the app then you may be able to operate as a reader app but otherwise, IAP is required:
3.1.3(a) “Reader” Apps: Apps may allow a user to access previously purchased content or content subscriptions (specifically: magazines, newspapers, books, audio, music, video, access to professional databases, VoIP, cloud storage, and approved services such as classroom management apps), provided that you agree not to directly or indirectly target iOS users to use a purchasing method other than in-app purchase, and your general communications about other purchasing methods are not designed to discourage use of in-app purchase.
2) A tour under the hood might be a ticket to the national park or may contain it as a part of a tour. Also it might include discounts for a real physical products.
You cannot use IAP for this component of value of a "tour". You must use a third party payment system for this:
3.1.5(a) Goods and Services Outside of the App: If your app enables people to purchase goods or services that will be consumed outside of the app, you must use purchase methods other than in-app purchase to collect those payments, such as Apple Pay or traditional credit card entry.
3) It's available on Play Store (and will be on website too in the near future), so not limited to App Store only.
Explore this guideline:
3.1.3(b) Multiplatform Services: Apps that operate across multiple platforms may allow users to access content, subscriptions, or features they have acquired elsewhere, including consumable items in multi-platform games, provided those items are also available as in-app purchases within the app. You must not directly or indirectly target iOS users to use a purchasing method other than in-app purchase, and your general communications about other purchasing methods must not discourage use of in-app purchase.