Females typically push when they're hungry, and the SD's and crosses I have often cross the line from "foody" to "stupidly foody" - one male even strikes the RHP.Getting him out for exercise often, especially the 3-4 days before his next feeding day, helps a lot.
The occasional exhale seems to be common, I've heard it from most of mine. The first few times it was rather disconcerting as it's a loud, forceful expelling of air. Maybe there is a particular reason for it in the wild? I've just noted that my retics are noisier and more expressive than my other snakes.