In my opinion, WPLANG Lite should not be used anymore as WP 3.4 improved a lot the size of the mo file loaded on frontend for core.
If Polylang Auto Translation breaks Polylang, you should its author on his support forum to report any problem. Of course I can try to help if he needs.
MaxSite Russian Date has not been thought for multilingual sites and of course will always force the language in Russian as it's its only objective ;-)
You can specify one date format in settings->general and then change it for other languages in settings->languages->strings translations using WordPress date formatting.