I feel your pain. However, this forum is primarily a user-to-user forum in which Adobe product developers rarely participate. Please repost your feedback in the official Adobe feedback forum: Recently active topics in Photoshop Family about Photoshop Lightroom
Sorry, but I miss the point of the rant. You say you do this and have problems in the import module. Would it not be MUCH better to import all the photos, open the lilbrary module and use the X key for reject (I also use the P key for definite keepers and no keystroke for the unsures). At any point you can stop, pause etc. without losing anything. At the end just hit the Command/Delete key (MAC) and you are done and never "trash hours of work".
I am not a profession photographer doing 3000 shots at a time, but I have had a lot of experience in database management in other fields. I have seen many examples where it is so much easier to change your own workflow, than it is to get a software maker to change their program to fit your preferred workflow.
Do you realize that the P and X keys work for pick and unpick in the Import as they do in Library (at least they do on a Mac, not sure about Windows). Unfortunately the Auto-Advance feature doesn't so you have to use the arrow keys.