Using family member's phone plan with my Apple Watch instead of dumbphone

I have a somewhat unique question (I hope). I attend a religious school that will be instituting a new "No Smartphone" policy in order to protect from the evils of the internet. We will be required to use a flip phone. Right now, for whatever reason, the flip phone market has yet to mature to the point of making dependable, reliable phones. I currently have an iPhone with an Apple Watch Cellular (without the extra plan). I want to know A. Can an Apple Watch search for content in a web browser, and B. Can I stick a family member's SIM in my iPhone then set up a separate family member account (for myself) for extending their Cellular plan with my own phone number? If I can, will it get messed up if they put their SIM back in their phone (assuming it's Android)?