Sounds right. Note: caffeine physical addiction lasts only a day or so. Similar with nicotine. The psychological addiction is far stronger and longer-lasting.
Depends on how much you're used to (http://www.hopkinsmedicine.org/press_releases/2004/09_29_04....): Typically, onset of symptoms occurred 12 to 24 hours after stopping caffeine, with peak intensity between one and two days, and for a duration of two to nine days.
Anecdotally, I know someone who was on three pots a day, and he had a miserable month when he quit cold-turkey. Some of that was withdrawal, but some of that was also probably him having to adjust to a wake-sleep cycle without the aid of stimulants.
