S5 viability for an X Pro1 guy?

Some background: I have been a Canon shooter, coming up through all of their xxD models, up to the 7D. Have some good zooms, and the macro.

Bought a Fuji X100 just over a year ago, and haven't touched the Canon since. Bought a X Pro1 two months ago, and haven't touched the X100 since.

I have the 3 Fuji primes, but at some recommendation somewhere, I got the Nikon 28mm 2.8 AIS. Then the 50mm 1.2 AIS. Now the 85mm 2.0 AIS. I use them on the XP1, manual focus is fine by me, and really, really like the results.

I have been looking at the back-to-film fad. Figured I could get an F2 or FE and use my AIS lenses. But every time I reach for the Buy button on ebay, reality sinks in and I think about the film costs, and general lack of immediate gratification, which is one of the cornerstones of my life.

But I DO like those lenses. So I thought, get a S5. They are not too expensive , and you are not building another DSLR system, you are only getting another platform for the lenses you already have.

I really like the IQ with the XP1 and (don't get mad at me) seriously doubt the S5 will match it. Although (beating you to the punch) I will at least be able to process my raw files in Lightroom!

So, after this prolog, my questions:

what will the S5 bring to me?
will the AIS lenses work?
wlll they autofocus?
will the camera meter?
is this just another way to throw money at something?

Disclaimer: asked this same question in the Nikon forum, re a D7000...