Subscriptions in Family Sharing

No. Cancelling and repurchasing while still in Family Sharing will not make them charge to you. They will still charge to the Family Organizer unless you have Gift card credit balance.

If you want to pay for them yourself, then you would need to leave Family Sharing or redeem gift cards onto your account that can cover their cost.

Family Sharing operates from the assumption that the Family Organizer pays for everything.

You cannot. While in family sharing all subscriptions and purchases are charged to the Family Organizer unless you have iTunes gift card credit balance in your account. If you have credit balance, then it will charge off of that before charging the Family Organizer's payment method.