Also returned on position on other keywords. Do this mean that my site is actually ok and don't need any changes? I do many onpage optimization for keyword "Lose poker why" before this started. Url in sig.
Now you are in #10. Be happy! Dont make any content and SEO changes. You should try to validate your code. 130 errors....too much ! Especially ALT attributes!
Try using the W3C Markup Validation Service. It's free, and will show you all the errors in your markup.
I use bitrix database, many errors is due automatic changes which bitrix made upon edting of a text. Can i in any way determine when this is was caused by bitrix?
Validation errors do affect your rankings when you are in dogfight for that top position, since you are already on page 1 error rectification can dramatically increase it by almost 50%, i would suggest you to take some professional help, also remember top fold of the serps receive almost 70% of hits, so you know what you are missing, good luck
As i understand i should be focused more on fixing errors closer to the top of the page or this is uninportant?