Yeah, that should work. And yes, thats how I would wire it also.
As for the smoke, if you have Kidde sensors: Integrating Kidde Smoke / CO Sensors into SmartThings Properly .
And if you really want to be able to pull a whole bunch of stuff into your system relatively cheap: [RELEASE] ST_Anything v2.9 - Arduino/ESP8266/ESP32 to ST via ThingShield, Ethernet, or WiFi
There is a lot you can do if you are willing to play with it.