those sounds when u turn the engine off are normal i guess, like TECH says. As for the sounds that shcverp is getting aint they normal? like when u turn off the AC system i guess the air ducts are closing or adjusting or somthing i dunno.
The breathing sound i get is when the engine is on, and yeah while cruising while the AC is on, or even when im parked by the engine is on, i notice a very low breathing sound somewhere from the left side of the engine (am not that engine expert to tell u where from exactly

hehe ) but yeah some kind of a recurrent breathing sound from there. i think its normal but i have to check that next time am @ the service center