Technically the circuit is correct. No need for pin swaping. It is OK as it is.
At first I know it is a bit confusing but trust me it is very clever trick.
The purpose of zener and the 2 transistors is to let the voltage raise up to say 40 volts on the capacitor and 2595 input. Then T1 is biased and switches off T2 so that the raising voltage cannot hurt the 2595.
This is repeated again on the next half period.
As for the dangerous this refers to the live voltages all over the circuit and the circuits connected to this. Other than this I consider it "safe" in a matter of speaking to use it.
Ioannis
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