Need wot switch + controller's tps switch?
 

My nitrous kit came with a WOT sensor. My controller, p series gauge also has this feature. It connects to the pcm for both rpm and tps (window + progressive+ wot)


Should I install the physical sensor in addition to the electronic control or is it fine?

You should be fine without the physical sensor and with it as well. You're only throwing another safety into the circuit. If you don't like the look of a WOT switch mounted to the TB then you already have a safety in place to ensure that you're already at a WOT condition, so why mount one?

You would be okay going both ways.