RealAuc,
I can't speak to the perfection issue, but let me address the other items.
1. A senior DOT is only superior to an IRS lien provided the trustee properly notifies the beneficiary of the DOT. This is a common misunderstanding. If the trustee did NOT notify the IRS properly, there is no 120 right of redemption and the IRS lien remains attached to the property. This is something I've personally experienced. In my case, I contacted the foreclosing trustee and asked them to verify that they had indeed done the proper IRS notification, and found out that they hadn't. Fortunately, they took ownership of the situation and resolved it by negotiating with the IRS at their expense to get the lien removed. I wouldn't be so sure that every trustee should do that, though I think there might be a legal argument that they would have to do that, but there a smarter minds than mine in this group to answer that question.
Meanwhile, until that is cleared up and your 120 days is up, I would not be in a hurry to put any extra dollars into the property.
2. Don't mistake a lien for ownership interest. A lien simply means someone is owed monies and the property is the surety for that lien. Short of a court order or statutory process they don't own the property just because they have a lien against your property. Also, property tax liens are filed by the County, not the state UNLESS the state provided money to pay for the delinquent property taxes for the previous owner, in which case there should already be a lien. But, if it's unpaid, to either the state or the county, your title company will consider it like a lien. Again, there a few attorneys in this group who can probably shed more accurate light on this topic and far more knowledgeable than I am.
HTH,
Trebor