Get a bk attorney, there are many other things involved here that one can't tell you about.
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Generally speaking, you have satisfied the 3 and 2 rule (at least 3 years since tax was due and at least 2 years since return was filed) in order to discharge income taxes due to the IRS. But, you should talk to a Bankruptcy attorney in your area to see if any exceptions apply to you or if the applicable Court looks down on discharging late filed returns and follows the decision of In Re McCoy.
If you qualify to file chapter 7, the answer is probably yes, since it has been over 3 years since the taxes were due and over 2 years since they were filed.
Probably, but you will "want" and experienced bankrutpcy attorney to review the dischargeability of the tax debt by reviewing the transctipt. There are certain events that may have occured that paused the various timelines. When tax discharge is at stake, you don't want to take any chances.