The good news is that bulb and flash-sync speeds (1/60 or 1/90 IIRC?) work without batteries in, but with the power switch to "on". Great for extra-long exposures - and something I couldn't do with my Canon AE-1s.
Love the XE-7. Fantastic camera.
The 50/1.4 will only be unsharp close up due to focusing error (I notice that often when people have a fast lens, they feel the need to do ultra-macros wide open and have way less DOF than would be desired - I used to do it too), it's a great lens at all apertures and lengths.