The issue is mainly when moving between apartments/houses. All the shifting weight and jostling in the truck simply weakens things too much. It's also not meant to be disassembled, and the particle board easily gets really banged up because it's so soft. And all this is even when trying to protect it with covering pads. (And sadly, none of your tips are going to help either -- fasteners simply pull themselves out of the soft particle board, because the board itself is weaker than the fastener/glue.)
A Billy bookshelf or Kallax shelving unit will hopefully survive a single move, especially if you can tighten/glue things further after it's been moved. But once you're talking 2-3 moves, forget it.
For that reason, for young professionals who move apartments every couple years in their 20's, it often makes more sense to just leave/toss their IKEA shelves/cubbies/units, and buy new pieces for the new place. It isn't durable across moves.
(Obviously I'm talking about "classic" IKEA particle board flat-pack stuff. If you're buying a solid wood table or metal lamp from IKEA then it'll be fine, but that's not what most people are thinking about when they think of IKEA furniture.)