I know that my rats sneeze like mofos... a lot of rats have that little bug that makes them sneeze a lot, I guess mice might be the same?
Rule #1, never leave your snake unattended with live prey...
Mice and rats are far from helpless, they can injure/scar/kill your snake. If your snake isnt hungry, he probably wouldnt do much more than curl up into a "ball" and let the mouse chew on him
To address your other concerns
Ball Python Not active-- No they arent very active, especially when they aren't eating, they conserve energy this way
Ball Python Hasn't Eaten-- Ball pythons can go for months and months without eating, 1 month isnt something to worry about. How old/large is your Ball python? Where did you buy him from? Its possible he was fasting before you bought him and thats why he still is on his fast.... or that the change in environment has put him off his feed for a bit. How long he can last without food all depends on age/size/etc