With respect to the unpaid federal taxes, you are not responsible for her taxes so long as you filed as married filing separately. If you filed jointly for any one year, then you would be responsible for the unpaid taxes for that year alone, although in that case you might be able to qualify for innocent spouse relief (which isn't granted very frequently, however).
With respect to the foreclosure on the condo and the condo fees, you will not be responsible for any deficiency on the foreclosure so long as your name was not on the loan the lender is foreclosing on; of course, if your name was put on the deed for the condo, you will lose whatever interest you had in the property, but you would not become liable for any deficiency merely because your name was on the deed to the condo.
As for the condo fees - I assume you mean the monthly charges for maintenance and the like - so long as your name is not on the deed to the condo and you did not otherwise agree with the condo's management that you would be liable for those charges, you should not be personally responsible for them; however, if your name is on the deed to the condo then you may very well be personally liable for those charges because you would then be an owner of the condo.
You don't say anything about whether you've been sued as well in the foreclosure action or the action to recover the condo fees; if you have, you definitely need to make sure that your divorce attorney is informed of that and is handling those matters for you. If you don't have an attorney at all, then you definitely need to get one immediately.
I am sorry that you are going through this, if your name is on the mortgage you are responsible to the mortgage company if your name is only on the deed and you are excused from the obligation by your separation agreement then you may not have liability, if you filed separately and did not sign the taxes you may have an argument, but you should consult a tax attorney on the specifics, take care and I hope that it works out.
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Mr. Atchley's answer was excellent. My question for you, though, is why haven't you asked your divorce attorney. If there is any possible responsibility, that should be addressed in your division of property. Your attorney needs to know this information, anyway.
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