I have XP1 with Fuji 18-55 zoom and 35m f1.4. The latter is superbly sharp and contrasty - better than my Nikors. I have the zoom for convenience - a walkaround - but this is no ordinary kit lens and does not deserve that title, it as good as most primes and at its wide end is better than the Fuji 18mm prime for the loss of 1 stop but gain of 3 - 4 stops through the OIS. I intend to get the Fuji 14mm prime when it arrives as my wide option and maybe the 54mm f1.4. I have a Kipon adapter for my non- G lenses so I can use the aperture ring on the lens. The Nikon lenses I use currently are 50mm f1.8, 85mm f1.8 and 180mm f2.8. The latter is a little difficult to hand hold steadily whilst manually focusing so I'm looking out for a cheap Nikon 135mm f2.8 which becomes a convenient and compact 200mm f2.8. (I didn't buy into this system to use long lenses anyway - I have my P&S D700 for that).
FYI. The adapter (all of them for this Fuji/Nikon combination) is about 1/2 the size of the 50mm f1.8.
If you have AIS or "D" type Nikon lenses then make sure you get the (cheaper) non-G type adapter.
If you want to use both types of lens then you'll have to get the G type adapter.
The sky is full of holes that let the rain get in, the holes are very small - that's why the rain is thin.