I've now found information regarding the questions that I originally posted. Since I've received no posted answers, this information is evidently not very well-known, so I am now posting the following link to it for others who may also be interested.
http://www.dpreview.com/articles/7230565274/fujifilm-shows-off-zoom-lens-on-x-pro1-and-denies-xf-lenses-allow-full-frame
According to the link, the 18-55mm zoom and the OVF will work well together once the X-Pro1 firmware is updated. Then zooming will produce a "continuous" tracking change of the frame lines, so that they show the proper OVF frame lines for all focal lengths in the range of the lens. The OVF magnification can be manually changed between its two values at the operator's convenience. If it works as well as shown in the demonstration video at the link above, then the zoom should operate rather successfully on the X-Pro1.
I'd still be interested in hearing first hand opinions from anyone who's actually used this combination.
--- Mike