openHAB MQTT question

[FredRoot]

Hi,

I have RF24 nodes which communicates to openHab via a Ehternet Gayeway. I have setup MQTT inorder to send configuration data to my controllers. I have used this openhab website to setup the MQTT. According to the website:
In addition to configuring MQTT publish/subscribe options for specific openHAB items, you can also define a generic configuration in the services/mqtt-eventbus.cfg file which will act on ALL status updates or commands on the openHAB event bus.

I have a "systeminfo" thing defined and everytime the the CPU load changes, OpenHab send all my sensor data via the MQTT topic.
So my question is:

1. Is it possible to reduce the number of data send via the MQTT eventbus? According to the webside it does not seem to be possible.
2. If no mqtt client is subscribed to the topic, will the MQTT broker (Mosquitto) still sent all the data?

[TimO]

@FredRoot

1. According to this, it's not possible:

In addition to configuring MQTT publish/subscribe options for specific openHAB items, you can also define a generic configuration in the services/mqtt-eventbus.cfg file which will act on ALL status updates or commands on the openHAB event bus.

2. Yes. The messages are published if no client is connected.