Like Skyrim.esm, Update.esm and Dawnguard.esm. Would it be allowed to redistribute these ESM's? I think I'm not the only one who finds those errors you always get when you load the CK annoying. I realize that Update.esm gets overwritten whenever a content patch is released, I would simply need to fix the errors in the new version again and release an update.

Without other game files these ESM files are kinda useless, on the other hand it would mean distributing practically all gameplay content data of Skyrim, so I'm not sure if this is allowed/legal. I also realize that it's kinda risky if a modder redistributes the base files, since it's a possibility to implement new bugs. Although naturally I would be extremely careful when merging changes and triple check everything. I would like to hear the community's thoughts on the latter point as well.

I doubt that's legal, and I doubt many people would want to download your copy over the official one for those minor bugs

I suspect if you posted up a free copy of Skyrim.esm on any legitimate site, it would get taken down muy pronto.

You could trying using something like https://code.google.com/p/xdelta/ which would mean you were only distributing your changes to the file and not any of Bethesda's code. I've never used it personally though so I can't say if it would work or how easy it would be.