Yes, it works no matter which server. You need 1) spare device always on 2) tasker 3) iTracing. Optional is Send/Expect plugin for Tasker (if you want to control it manualy).
No it doesn't have Wi Fi, it is only a switch to be used at home in the same room as a replacement for wall switch. I tested in my flat and it works from 2 rooms away (2 concrete walls), so any size room is ok.
No, moto gear is connected to tracker via BLUETOOTH, and to the bulb via WIFI. So it doesn't matter how far away it is from the bulb. It matters how far away it is from the TRACKER (which is on Bluetooth)