Page location and page turn in there for syncing across devices, that's fine - ask the user 'sync across devices', if they say yes, not a problem. if they say no, don't send the data. Data that is stored would be something like 'currentlocation[$bookid] = $location'. Storing historical information (user was at location 1219 at 2020-01-06-05:12:41) is not required for that function.
Philosophy should always be store the minimum amount of data to provide the function that the user wants.
IP address is transitory and shouldn't be kept longer than needed for the tcp session, maybe it sticks in firewall logs, but that shouldn't be used for anything other than security.
goodread account details would only apply if you connect to goodread, I'm not sure what the benefit of that is, but I could see that 'user abc123 read this book' is useful data - again ask if you can send the data.
