Beginner questions, 230v switch on PCB
1) Trace widths depend on amperage, clearance on voltage, you can find many calculators and tables online, e.g. (based on IPC-2221 norm):

Standard PCB trace widths?

Minimum clearance between two traces that have a potential difference of 1000VDC

Generally when using traces for power distribution, you can go "as wide as you can" to avoid power losses and when using dangerous voltage, keep the clearances as big as you can unless you really need to cut down on PCB dimensions.

2) Never seen such, bigger and more robust ones of course exist. Also if you want to have a small button switching directly 230 V on its pins on a PCB, I would keep my hand far away from it. I would probably use a small button triggering triac or relay if you have some DC voltage available on the PCB. Differences are well described here:

Triac versus Relay