i have a 305 carb automatic and when i start it, after a couple of seconds it dtall, i have to keep it at idle by puching the gas pedal ever so gentally. but when its warmed up its fine. also when i turn the car off sometimes it wont shut off immideately,it does about 2 more revolutions and it sounds like death

ive narrowed it down to choke adjustment/sticking, vacum leak and possible bad fuel pump? please help its my daily driver!!! and stalling in an intersection isnt fun!!!!!!!!!!
thanks