A:AnswerI am pretty sure you can use the thermostat without WiFi but it really is designed for use with WiFi. Without WiFi this thermostat will be no better than a standard programmable thermostat. With WiFi, access from a smart phone and an outdoor temperature reading are the only additional features.
A:AnswerThe WiFi Smart Color Thermostat has support for a forced air system with 2 heating stages using W and W2 wires. It does not have anything more than a single G wire for the fan. I don't know if that is enough for your Goodman furnace.
A:AnswerYes. You should be able to unclip the faceplate and use the existing holes to install the new thermostat. The important issue is getting the wires in the right spots. This thermostat is very bright compared to the old one, forcing me to close the bedroom door.