Hi Will
Yup, I completely expect it to be a very selective process, there are some legendary lenses that I am sure would perform excellently and are reasonably priced when compared with tech lenses and even some 35mm glass, I have no doubt that a lot of lenses will be average at best. Having used a tech cam quite a lot, I really like the idea of rise/fall/shift within the image circle, so much easier to work like that for me, high quality lenses designed to cover 6x6 or 6x7 should work perfectly presuming as you rightly say, that the sensor deals with the shifts adequately. Without having ever seen an Actus or Universalis, I wonder about the weight of the lenses on the front standard and whether they hold ok, probably not an issue at all but thought I'd ask!
Cheers
Mat