Lolicon isn't derived from lolita. Lolicon is someone who is into young looking girls, it's not a genre, it's a personality trait. Lolita is indeed the name of a Russian book, and lolita means "sexualised girl", to make it easier for you, slutty, revealing etc. Loli is a further abbreviation of lolicon, though it is originally from lolita, and has the slang meaning of a young looking girl.
To help you: Wikipedia
Also I'm done with the debate, no one uses the definitions you provide and I've asked tons and I mean tons of people for their opinion. None agree with you. Cya.
Very simple question before you leave.
When you see a loli, what goes through your head? What words pop up to mind.