Non-isolated circuit question (connecting to notebook)
This is just foolish. All metallic parts on the outside of the laptop have the potential to go live. I will describe one scenario.



simulate this circuit &ndash; Schematic created using CircuitLab
Figure 1. A break in the neutral connection will cause the laptop to go live.
In the event that there is a break in the neutral (and this can include a fault in the building wiring or the neutral contact of the mains plug disconnecting before the live contact does during an unplugging action) your whole circuit will go live.

All exposed metalwork will be at mains potential.
Various parts of the plastic insulation (touch pad, etc.) may not be rated for insulation at mains voltage.
The DC power supply, if connected, introduces a path back to mains - even if only through the filter capacitors.
You should never assume that neutral is at earth potential. If you get a short to live on another circuit the neutral voltage could rise to half supply voltage until the protection device trips.

Your question gives the impression that you might not listen to advice. I hope I'm wrong.