Finally I’ve got the answer of the question I was searching for a very long period of time.
In short: It is impossible to have big multilingual WordPress website that will work fast.
In long: The most popular WPML plugin is a garbage! Theme developed by me is producing 217 SQL queries for the index page, whereas wich WPML this number becomes 745!!! This is Impossible !!
And do you know what WPML documentation advices? Use another shitty plugin like WP Super cache or Total cache for static html caching of HTML files.. com on… this is not a solution.
So my verdict would be abolishing WMPL plugin from website and forget about that shit forever.
The solution: hm… I’m now on the way of searching for solutions, the obvious and straightforward solution is to create a website per language ….or through away WordPress and write your own simple and powerful CMS :)