Nonstick Pans: Purpose, Cleaning and Heating
Well nonstick pans were created so that the likelihood of food sticking to the surface of the pan is reduced and the idea that they were designed to be used without oil is not true. You certainly can use it with oil.

Secondly, cleaning oily residue from the pan can be done as mentioned here. It is suggesting to do the following:


Fill the pan with water
Pour in half cup of vinegar
Bring the mixture to a boil
Allowing the oily residue to float on top the surface.
Use a paper towel to skim off the residue
Pour out all the liquid in the pan
Finally, wash the pan with soapy water and non-abrasive nylon.


Thirdly, about heating nonstick pans, its alright as long as you don't cross the limit of 470 °F/243 °C as it will cause the Teflon surface to melt and release toxic chemicals. When heating up a nonstick pan empty start with a low temperature instead of going all high at the beginning which might pose a risk. The previous facts were taken from here.