A) 3 is the best, it uses lithium batteries. 1&2 use a rechargeable pack, most of which need to be re-celled. There was a AA pack available, but that is difficult to find. There were also some upgrades to the v3 that are desirable.
B) Yes, probably better, but often slower. (limited to the RB and GX lenses I had)
C) It is SIGNIFICANTLY larger and heavier than a Hasselblad. It is significantly larger than an RB.
D) There was one model made without shift or tilt (GX 680 III S).
E) I have only used the 180mm on your list, so I cannot compare.
Also: you need a special cable release, and they are different between the I & II and the III, and they are not compatible. And they are hard to find (hence $$$)
The sliding loop finder is useful if you plan to use tilt.