If I use the same account for multiple tablets, will my settings in one tablet affect settings in the other? For example, if I “remove all” magazines on one tablet, will the content be removed on my other device the next time I sync/log in?

Your My Favorites library will sync across multiple devices. If you add or remove titles in My Favorites on one device, using the same account on another device will also see these changes. If the changes don't appear, you may need to pull down to refresh or log out and back into the app.

Please note that downloads do not sync across devices.