Local apps usually still require installing dependencies from the network, call home for updates, use cloud storage or sharing, and may send telemetry data. Different levels of strictness.
No, local apps can be installed from a local storage just plugged for the occasion, with all its dependencies included.
Local application is local, it doesn't deal with network in any way, except if end user goal require to send/receive some external information. So a calculator or a solo game doesn't require network at all, but a chat app or some MMORPG have a legitimate need to access network, but only to communicate with other users.
Telemetry is just an other word for spying. Spyware integrated used to be considered a clear sign of malvolonte project.
Software update can be put as a separated concern.
