Can someone on our Wi-Fi read other users' traffic?
It depends on the Wi-Fi security and on what is encrypted above it. On an open network, or one where everyone shares the same password, a person on the network can, with some effort, see or redirect other users' traffic; WPA3 makes passive reading much harder, and WPA2 or WPA3 Enterprise with individual logins separates users better. Client isolation on guest networks stops devices from talking to each other at all. In practice most traffic today is protected by HTTPS, so the bigger risks are redirection to fake login pages and attacks on devices that still use unencrypted protocols, such as old printers or cameras. Keep guests on an isolated network and staff on individual logins. NetSenX does not manage Wi-Fi; on monitored segments it shows which devices talk to which and flags scanning from a newcomer.