the range, im not sure, i imagine its above your stove, the exhaust/light combo. but 40 amps?, might be something else.
for now if its in use leave it
since you already have the 2 pole 30amp for the dryer, just leave as it was for the dryer to begin with, and run one or two extra lines depending on how many lights you have to connect ( sorry i dont remember what you have going there)
just pick up those single pole double breakers, as many as you need for the new and existing lines in place now.
if you have to,shutoff the main breaker so your not working live, use bx or romex and make sure its grounded.
i hope it helps somewhat, im gonna be gone for a while and i hope youll get the help you need from friends or other members here
good luck