If you don't want to use Samsungs' system, why would you want to use their sensors? This sounds very much like a no-expenses-soared effort to re-invent the wheel.
Their multi-purpose sensors (temp, physical movement, magnetic contact) and their PIR sensors (PIR motion, temp), are very well engineered, power efficient, reliable and in the price range where it isn't worth trying to reinvent the wheel in that case.
On the other hand, their hub requires a wired ethernet connection and when used in a mobile environment with a wifi-to-wired adapter, is very unreliable.
I already have my own ESP8266 monitoring device for our RV (wired temp, motion, GPS) that connects via wifi to a jetpack. Eventually will change to something like Particle Electron or Hologram Dash to eliminate the jetpack. But I'd like to use Samsung's sensors to add some remote sensors, thus the original question.