I just started getting severe pain in my lower left molar that goes away with advil (ibuprofen). I think it is my wisdom tooth. Is that dangerous/fatal/treatable?

Yes/rarely/yes. It does sound like an infection where the imflamation is causing the pain. The danger with these is when the infection spreads to the surrounding tissues and creates an abcess. These can be very bad infections and certainly the tooth should be looked at.
No, no and yes. Tooth pain generally is not dangerous but should be evaluated by a dentist. We don't want infections to go untreated, in case your symptoms are from an infection. Besides, seeing a dentist early may prevent more extensive work later on.
Wisdom molar pain. If a wisdom molar is troubling you you should see your dentist you should possibly need to have it extracted and looked at with an panoramic x-ray .