1. Yes, when in Vector you have a snaky line at the bottom of the tools this allows you to alter smoothing giving a much smoother path for shaky hands. Not available under Live or Pixel brushes.
2. There was an experimental feature which allowed for the creation of straight lines if you held the pencil at the end of a stroke. I'm not sure where that feature is at. I thought it was added, but for me my lines are not straightening. There is a shape tool which you can use now but it seems to mainly be for filling shapes rather than drawing a stroke.