How do I install a ceiling fan without creating holes in the ceiling?
Repairing the holes in your walls doesn't need to be such a daunting task.  Have a quick look at this video on how to patch your drywall:

This Old House - Drywall 101

It will look far better in the long run if you let the wiring be run within the walls and learn how to patch them.  All told the drywall (you can often get small 2x2 boards for patch work at Home Depot), cutting knife, spreaders, joint compound (premixed)and tape will run you around $50.  By contrast running electrical in conduit will cost you just that much for the conduit alone and look far less appealing.