But how about actuators?
Yes pub-sub pattern is applicable to actuators.
Is this the way to go with actuators?
This is one of the ways to go and this is booming because of many cloud providers like
AWS IoT as a service support MQTT(over TLS, WebSockets)
Google's Google Cloud pub-sub messaging service
Microsoft's IoT Hub with MQTT support
trying to ...
How about security, thinking on using this for doors for example. Is it possible to publish a open door event from anywhere? How easy can it be hacked?
According to the documentation RabbitMQ uses TLS/SSL. So security level is as good as these technologies. If you check RabbitMQ- TLS Support here are your examples about using SSL, acquiring server ...
I think your switch device should be connected to a hub (domotic box, zwave controller,...) which handles all these events, so the switch should be dedicated for low level interaction with objects (zwave,433Mhz,...)
Smart devices are very limited on battery so the less they operate on the network the longer they last.
I'm not aware of any general purpose internet-enabling physical interaction devices. Most of the IoT applications which I've come across so far have been integrated offerings, aimed at specific use cases. Vendors also seem to be trying to avoid encouraging plug-and-play systems where you can easily chose the sensor provider independent of the back-end.