I don't belive it would be possible for users to add them themselfes because to me it seems like it is some sort of extension, and then it maybe requires SSH. But if many users want them, I belive an admin gonna think about it and deciding if it is needed or not.
you mean like if you make a template or something, you want to put it for download on your site? That's ok as long as it doesen't break the law and/or TOS in any way (like copyrighted material, hacking tools, porn and malware is against the TOS)
lol hahahah nice :P. Sometimes those are cool when the public can see them, but if they are placed in a CSS file, it's useless (look at the bottom of the default wordpress stylesheet)
^from the bottom of the style.css in default wordpress style
We have the same thing in the 9th grade in primary school in english, swedish and math. This year they gonna make it for every thing you do in school, luckily I missed it with 1 year :P