Are there limits to appropriate weather conditions during the application of exterior paint? How long do different paints take to cure, and what temperature is too low? Within what time span of application? (e.g.: can I apply latex paint to a shed if the temperature is expected to dip below 55F within a day or two? what about rain? what about oil-based paint?) Thanks in advance for any help!!

Not to not answer your question, BUT.
The best anyone here can do for you is to give you general guidelines on painting. As a rule of thumb, the more humid the conditions the longer it takes for any type of paint to dry. As for your other questions, paint manufacturers produce various types of paint and their application requirements can vary. To receive the best answer you should visit various paint stores (PPG, Sherwin Williams, etc.) and see exactly what each has to offer you for the area that you live in. If service is poor, then take the time to read the labels on the various cans (which you should always do anyway) and choose the type of paint that is most suitable for your application. BEST OF LUCK!!!!