Everyone is differen. Most people take a day or two off from work. If they were particularly difficult extractions it may take up to a week. If you have severe pain after a few days you may have a dry socket and need to see the surgeon asap. Make sure you take your meds as prescribed. You should not need pain meds after a few days but you should always finish any antibiotic prescription.
This really varies. That's very difficult to answer in advance. It becomes easier to answer after the extraction. It depends upon the difficulty of the extraction, your pain tolerance and the type of work you do. With a simple extraction and desk work, the next day should be fine. For an impacted tooth and heavy labor or speaking to people, it could be a few days or longer. Ask the surgeon what he\she thinks.
Longer the better. I typically recommend you have a couple days to rest after having teeth out. The main reason is that you have undergone a minor surgery and your body needs time to heal. But I have had some people back to work that afternoon (against my recommendations). Give yourself at least one day to rest if possible.