I like those relays. Is that 3 different switched outputs? One thing I always liked about european wall switches is that they give you more room for components. I would like to use a similar type of relay for my in-wall switches, but with the way US single gang wall boxes are, there is a pretty narrow space constraint. I might be able to fit it if I did away with the thermal fuse, but I don't want to give up tat bit of added safety just for that.
Added sketch, which also supports an additional mini PIR sensor. It's what I needed, you can comment to #define out.
Also changed the regulator to a smaller one, which supplies up to 100 milli Amp, which is plenty enough. That way I can keep the circuit smaller on the PCB. Which allows me to create a smaller housing.