Tradish Pro is billed through the App Store or the Play Store, so you manage or cancel it in your store account, not inside Tradish. Whichever store you used to buy Pro is where you change it.
Canceling turns off the automatic renewal. It does not cut Pro off right away. You keep Tradish Pro (unlimited imports, Cook Mode, and Nutrition Facts) until the end of the period you have already paid for. After that, your account goes back to the free plan with its weekly import limit.
Nothing you saved goes anywhere. Your recipes, cookbooks, plans, and grocery lists stay exactly as they are on the free account.
No. Because the subscription is handled by the App Store or Play Store, you cancel it in your store account using the steps above.
No. Canceling only affects the Pro features. Everything you saved stays put.
Open Tradish and upgrade again, or resubscribe from the same store. If you had Pro before and it is not appearing, try Restoring purchases.
For what the subscription includes, see Tradish Pro: what you get.