Chris, I do not use the Adobe suite or Quark, so it is best if others comment.
Re MS Office, my experience is that it works just fine. I suppose there are, or may, be issues depending on the version of Office that your dad is using. I used, without problem, Office v2001 until Office X was released. Office X is significantly better (IMNHO). In the upgrade from v2001 to Office X, I experienced few, if any, problems with Word, Excel, and Power Point. I don't use Entourage, so again, no first hand experience. But from the number of posts on MFI and elsewhere, that seems to be the weak link in that package.
HTH
Harv