Home electrical safety devices

[stuffies]

Hello all. Recently we had our very old Heinemann ELCB replaced with an RCCB without overload protection. The lack of overload protection made me wonder if we really have all the needed electrical safety devices.

I'm not an electrician and I'm working from the assumption that everything I thought I knew about electricity is wrong. I am a total noob when it comes to electricity. I have a few questions I'm hoping you'll be able to answer.


The installation...

We have 3-phase power.

We don't have access to the municipal meter box on the sidewalk. Its post-paid power.

Here is our own meter box on the outside of the house. There used to be a switch/breaker in that opening below the round window, but was replaced by the switchover device on the left we had installed to connect the generator.




Here is the distribution board and the newly installed RCCB.



Here is the old ELCB we had replaced. Pressing the test-button didn't trip the switch. Electrician confirmed the device is faulty. I couldn't find out if it had built-in overload protection.



My questions...

(I love full detailed explanations, so please don't hesitate to elaborate)

1) I understand the new RCCB won't protect against short-circuits (live wire touching neutral) or any other situation where too much power flows through (unless the difference between the live and neutral is 30 milliAmps or greater), correct?

2) The switches labeled "plugs", "ligte", etc are the miniature circuit breakers (MCB's) and they're supposed to trip if too much power flows through the circuit, correct?

3) What are those numbers printed on what I assume are the MCB's?

4) Should I have a circuit breaker (that trips if too much power flows through) re-installed in the meter-box on the outside of the house?

5) Should the municipal meter box on the sidewalk have a circuit breaker with overload protection?

6) I record our municipal meter readings every month (read at the municipal meter box on the sidewalk). There are 3 meters (since we have 3-phase power). One meter always has a low monthly usage, the other one a higher usage and the last one the highest usage. Since the new RCCB was installed it seems the highest-usage-meter now has the second highest usage, while the previous second-highest-usage-meter now has the highest usage. I assume this could be because the wires in the distribution board might not have been connected to the new RCCB exactly the same way they were connected to the old ELCB. Should I be worried?

7) Can you see anything missing/wrong safety-wise?

Thanks in advance.