Problems with interference in sensor readings

Thanks a lot @pylon!

Some resistors are been omitted in diagram to make the diagram faster.
The infrastructure was not set up by me.

I don't understand 2 things:

1 - Shielding may be necessary: What do you mean by that? What shield can be necessary?
2 - DS18B20 are no set to non-parasitic mode : How i configure correctly this option in code?