Is my extra virgin olive oil rancid?
Good olive oil is supposed to have a peppery burn in the back of your throat.  It is also not uncommon for it to have bitter elements.  There is no way to discern if your oil is bad by your description.  Olive oil that has been exposed to heat or light, or is just old, will no longer smell fresh.  Fresh olive oil generally has grassy aromas with some olive mixed in.  Rancid oil might smell waxy, some describe it as smelling of old crayons or old walnuts.  It might taste fatty, as opposed to fresh and grassy.  If it is rancid, couple of teaspoons is not going to cause any harm.