I think the main benefit of the Pro at this point (since the Air is so powerful now) is that it has a super drive, so if you have a need for DVDs or CDs and burning them, it's a great benefit. But if not, it's almost easier to just go with the Air for the light weightness of it.
Also, if you wanted Retina display, only the Pro has that, so you'd have to go Pro for that.
As far as Pages vs Word (Office), I'd say go with MS Office since that's what 99% of your professors are going to be using and any odd formatting might make them mad. Your school probably even offers Office for free to you.