John,
If you don't need the camera to be pocketable I would go for interchangeable lenses. Much more flexibility and not heavy either.
If you want the OVF go for the X-Pro1 but really (although I own the X-Pro1) the X-E2 and especially the soon to be announced X-T1 are/look a much better proposition IMO.
Please also take into account that the OVF of the X-Pro1 does not work well with all lenses.
The 23mm is an excellent lens. I own the X100s as well. In my opinion the XF 23mm is way better, wonderful rendering, one stop faster, closer focusing as well, the X100s gets kind of dreamy up close.
I also own the 14mm and the 35mm. I would be hard pressed to pick a favorite. The 56mm is pre-ordered. The only lens IMO that is missing is a fast 1.8 or 2.0 90mm prime.
If you only want to buy one lens initially I would go for the 23mm or perhaps the 35mm which is longer but slightly sharper. The 14mm is perhaps the best lens but can be too wide for a lot of uses.
Thanks, Joris.