Normally, you are not allowed to elect the foreign earned income deduction on a late return; however, if no tax is due, you are allowed to elect the foreign earned income deduction. Furthermore, if no tax is due, there is no failure-to-file penalty.
In your case, if your unearned income is less than the standard deduction, then you're fine.
I don't know if the IRS will come after you for returns before 2008, but it sounds as if you had no income, and they usually demand only 6 years of back returns even for "tax protesters", so you should be OK, there. Note that you cannot file your tax return for 2013 until the forms are finalized, probably in early 2014.
my father (also an American citizen) living aboard has been filing income tax so late, some times 2 years late, he send them by mail, so i was Confused what to do, I'm planing to come back to U.S. so i just want to make sure i will be in the safe side
By "standard deduction", I meant "standard exemption" (about $3300 for 2013). Your previous question indicated that you are married, and your wife is an NRA (non-resident alien), so you have to use MFS (Married Filing Separate), and there is no standard deduction.
I don't see any likelihood of criminal prosecution, even though you have technically violated the "failure-to-file" statute.
before 2008 i was still studding in collage, and my father was filing my name in his income tax form
And, if you get all your returns (2008-2012) filed before you return the US, there is very little likelihood that the IRS will attempt to seize your assets, which is the other reason you might have difficulty leaving the US again.
If there were any tax due on a correctly filed tax return, then you would not be able to use the foreign earned income deduction/credit on a late-filed return, and you would then probably owe tax in your 2008-2012 returns. If you pay that tax, with penalties and interest, then you would be able to leave the country freely.
but a didnt come back to U.S. since 1991 when i was 8 years old, and there is no income tax for 21K $ yearly, and I'm planing to come to U.S. and live there & work, then i will pay a monthly income tax
Sorry, I had a browser crash. Once you start working in the US, you will owe US taxes. But that doesn't affect any previous-year taxes.
that's ok, so in my case i don't owe any income tax right? I'm on the safe side, i just have to file all the forms, right?
Yes, that's right.
is there any important information i have to know about my case? being late to file?
You can file returns for 2008-2012 with the FEIC only if no tax is due on those returns. However, there is no special way to file the returns (except that returns after the extended due date (2008-2011) cannot be E-filed). All such returns are sent to the Philadelphia office, as are all returns with a non-US address.
so there is no Violation of the law for being late to file, especially that i don't owe any income tax?
That's correct. Failure to file can be a criminal offense, but that doesn't apply if there is no tax due. If there were tax due, that might be different.