Can't comment on lens interchangeably of the two. Why not carry a couple of extra batteries in your bag? I have around 6 of them in my bag for my Mamiya 645's. I got the batteries on Amazon.com for cheap.
Yes. But don't make the mistake of setting the shutter speed with the dial on the body. Did this because I've used RZ lenses for years and old habits die hard. Felt real stupid.