No worries, I'm happy to help.
1) That is not typical, generally I would expect only about 5%-15% CPU usage from our Raspberry Pi agent software, depending on the model of Pi, and assuming no other major software running at the same time alongside it. We did just push an updated Pi Agent yesterday specifically to address some resource consumption issues, could you tell me if this behavior has persisted into today?
You can check if you have the latest agent, 220.127.116.1138, by running the command
Another option if you find the resource consumption of the Pi Agent to be too heavy is to connect the Pi via the MQTT API. Then the only activity is publishing and receiving MQTT messages, and there isn't all the background work of monitoring your running processes/CPU/RAM/etc etc
2) I'm not sure I understand exactly what you mean here, let me know a bit more and I can give a better answer. If you mean basing a trigger off of the Pi 'Network Speed' widget, not at this time. You can make triggers based on device Online/Offline status, however.
3) You shouldn't have to make any additional configuration - Cayenne uses RealVNC to establish a connection and should only require that VNC is set to 'enabled' in
raspi-config. Perhaps you could run that
tail -f /var/log/myDevices.log command again while attempting the remote connection and see what if any error messaging you get.