At the end of September it say that this month's total would be finalized the 10th of October. However, my balances are totally different. Is something not being reported right because this is the first time I ever noticed?
You have to ask for support, it seems fishy. Go to google payment support section and drop a question.
The total estimated earnings you see on the reports page should be different for the actual earnings on the payments page. It's normal if it is a small difference, but If it is a big difference you should contact Google or start wondering if you are not receiving fraudulent or invalid clicks on your ads. That will cause a big difference betwen the estimate and the actual earnings.
Yes, don't worry, nothing bad is happening, only they pay you what they want and you have to accept it anyway, so no need to worry about that, only worry about your site.