software bugs on one device will not kill all e-readers
I have the kindle DX because of it's larger screen, the kindle 2 screen is about the size of a paperback, but it changed pages slowly enough to be an annoyance to me, the DX had enough text on the screen to make the annoyance significantly less. The kindle 3 and newer devices have a newer generation of screen that changes significantly faster (as well as providing significantly better contrast)
the kindle DX has problems with pdf books similar to what you describe with long documents, but not with any other format (and I understand newer devices are signficantly better)
The other problems you are dealing with are software bugs on your reader, and not ones that I have heard of on kindles.
your conclusion that these will doom e-readers is like saying that one model of smartphone has problems, and so all smartphones are doomed.