Is there a way to easily add image swap/rollover to images on a Basic Page?
You can try Rollover Filter module. This is the only module for rollover effect AFAIK.


  This module provides a simple method to enable content editors to use
  image rollover states. It makes no checks against the referenced image
  types, it simply converts [rollover] wrappers into actual rollover
  images. It does use a Javascript based approach, and causes no harm to
  images in an environment where there is no Javascript.