Despite numerous patches, the PC interface for Skyrim still has some serious problems with keymapping. You can see the problem very easily by assigning "activate" to the left or right mouse button. This one minor change causes multiple issues, the most glaring of which is that it becomes impossible to pick up a readable book or scroll (which essentially makes parts of the game unplayable).

There isn't any way to directly reassign keys for the user interface (like e for "take" or r for "drop"), but the game still changes them if you alter the corresponding keymappings outside the UI (changing e for "activate" also changes it for "take"). Letting the UI keys be mapped independently would basically fix this completely.

I'm sure I'm not the only one who prefers to be able to left click to interact with things rather than attack them. It's been extremely annoying to have to work around the broken UI mappings to be able to use the setup I'm used to playing with. It might not seem like a big deal, but struggling with the interface and keymaps has been bothersome enough that I've yet to actually play more than an hour or two without quitting in irritation. This wasn't a problem in Morrowind, Oblivion, Fallout 3, or Fallout: NV, and I hope the lack of such basic functionality will be officially addressed in the near future.