I'm designing a smart socket that will route 240V AC Live and Neutral to a voltage regulator and also to a relay that will control the current flow. Due to the limited space, it will be easier to route the live wire on the top layer and neutral on the bottom layer as shown in the diagram below where the red track is AC Live and blue is AC Neutral.
The PCB is two layers with a thickness of 1.6mm. Will there be any problem routing it this way? Will it create a voltage potential or capacitance of any type? Secondly, the relay can handle up to 5A, hence the tracks should be able to handle 5A too. Based on an online PCB trace calculator, the trace must have a width of 2.77mm which is quite hard to fit in the limited space. If I leave the traces to be exposed copper, can I then reduce the trace width?