A healthy snake can usually go a month or more without food before any serious bad things start happening, though it's really not recommended to let them go that long without food unless they are in brumation. (I haven't brumated my snakes yet so you'll have to ask someone else for more information on brumation.) As for handling her, I'd say yes, two days should be enough for her to have calmed a bit, just try not to be afraid of getting tagged, and don't 'reward' her by putting her back when she does something that makes you uncomfortable, wait until she's calm.
Mouse traps are classed as a quick-kill trap, similar to the Conibear trap used for foxes, wolves and other fur bearing animals. The requirement for these traps is that the bar come down on the head or shoulder with sufficient force to kill the animal within a very short amount of time. (I'm not sure the exact length) With the frailness of mouse bones, a mouse trap should shatter their skull (instant death), or crush their chest (spine broken, so no feeling, and the heart is compressed, death very quickly). A mouse trap is designed to kill mice, If it didn't work extremely well, then it wouldn't sell.