Can S5 take my S4 thermostat houseing
 

Just wanted to know b/c i have a plastic one with for some reason 3 bolts and i believe my thermostat is sticking. Can i just swap them?

No, neither the thermostat nor the upper housing/neck are interchangeable between S4 and S5.
Just get a new thermostat and use your three bolt housing.

when you replace your thermostat, use an oem mazda thermostat. available at your local dealer or here at www.mazdatrix.com