yeah it's slang and it means "for sure"

It sounds nice, much nicer than other languages, kind of soft and mellow. That is english with American accent, english with British accent sounds nice too, but more uppity.

The border, and after that, the next country.

That you guys are close to Russia and maybe speak Russian as well. That is all I know about it :S

I think you mean what is the difference between language and tongue, you see people use those two words to mean the same thing (language) for example some people may ask you "what is your mother tongue?" or native tongue or first language etc etc and they all refer to language. But usually it is more common to say language, cause tongue is more used only to ask the question "what is your mother tongue", refering to your first language or native language.

Find a lot of new friends. I'm going through the same thing btw, and befriending a whole lot of people is helping.

Hey, I'm an advanced english speaker and would love to practice with you or other advanced/intermediate speakers so just drop me a line with your info if you wish me to add you. Already sent you an invite girl, see you on skype!