Can I use a bat handled toggle switch instead of a boring standard toggle switch on the wall?
The ONLY way this would be code complaint (legal) and safe is if the switch were solidly mounted to a metal plate, which would in turn be mounted to a grounded metal box. If you have plastic boxes there will be no way to ground the plate through the box. 

NO! Soldering is NOT an option as this is expressly forbidden in the code. You MUST have a solid mechanical connection even before soldering. Having said this there is no means or provision for any sort of mechanical connection to that switch or to a switch plate, unless of course you nut and bolt the ground wire to the plate, but this adds a visible screw head to the finish side of the plate.

Almost certainly you'd need to get a stainless steel blank plate and drill your own hole.