1.8 is good for hand held shooting in low light, shooting in low light, you can get a very shallow depth of field meaning not much of the scene is in focus with lots of bokeh, i like to shoot the local car shows at night with mine hand held. i got some great low light car photos with it.
35mm is not really a portrate lens, its good for shooting a group of people indoors but you get close to one person with it your gonna get too much distortion. average portraate lens is around 70mm or narrower, check out the link i posted about that.
if you have a DX camera take the lens focal length by 1.5 so that 35mm is really a 52mm equivalent on a DX body, a 50mm lens on a DX body is the 75mm equivalent. you would really want at least a 50mm-70mm lens on a DX camera to do portraits of single people. with that 35mm lens you can step back and get a group of people in the photo and it will look fine but get close to one person and you will get funky results as showin in the link..
Face distortion is not due to lens distortion
that 35mm 1.8g is a very sharp lens, i had one but decided to sell it and i plan to pick up a 18-35mm 1.8 lens, i really like to be able to zoom, not a huge fan of primes but primes are usually going to give you excellent image quality so allot of people prefer them over a zoom.