Thanks to all of you who have responded. We very much appreciate you taking the time to share your thoughts.
We are making excellent progress. Our app reliably connects on demand, can add and delete books, and can invoke reader apps. We are now working on UI details, book/folder routing features, etc; and on error handling. What a joy error handing is in networked environments where the connection can disappear at any inconvenient moment.
Regarding laptops and security: we decided to do two things:
1) The calibre smart device driver can be easily started and stopped without going to calibre's device plugin customization. There is now a line in calibre's connect/share menu to do this. Reason: to ensure that no user has the smart device driver running without explicitly enabling it. For this reason the driver ships in the "off" state. It must be turned on, something that is easy to do. When the app fails to find calibre, it will give instructions for how to turn on the calibre driver.
2) If the app finds more than one connection-enabled calibre library (e.g., in an airport), it asks the user which one to use, displaying the name of the computers accepting connections.
Some more info related to security:
- Users who are permanently on networks considered safe can tell calibre to start the driver when calibre starts. From then on, no intervention in calibre is required.
- Users who travel or who are paranoid can start and stop the driver when desired. Doing either one takes 4 clicks.
- The device/calibre connection can optionally be password protected. If calibre has a password, then the user of the app must supply that password.