Are there any issues connecting Neutral and Live at once to the supply line?
Your circuit diagram looks perfectly safe.

A two pole isolator is often used where the need is to make a circuit safe to work on, not simply to turn off the power.

Earth should not be switched, your diagram looks correct.

Disclaimers  As always, check the law and codes in your country. You might need to have a professional certify it safe. There will be rules about the type of wire, termination, labelling etc. The body of the 2-pole switch should also be earthed, and the earth cable should run in the conduit between them, not taking a short cut. The power should run through the switch, not there-and-back. You are probably not allowed to fasten the cord of a portable device to the wall in any way, or run it under a carpet or floor.  You're probably not allowed to mount a hand tool in a permanent way. I can't tell you that your system is safe, but the electrical concept is not dangerous.