Starting with, this property now is owned by the heirs of the original mortgagee (note holder) and there is an unsatisfied debt on that note that they now own. 

-------------Other than that you are going to look at some of the Stated Lenders...who will lend to a LLC with 25% down ...if you do NOT  have residency Visa's.

You could be held in contempt of court if you cancel your check and the lien holder can sue you the sales are buyer beware.When did the house burn down and was demolished.this might be your saving grace.Obviously contact an attorney immediately When did you do your due diligence on the property,did you ever drive by it.How much did you pay.good luck

NO title insurance though but on those really did not need it.. as I self insure myself in these deals.. if your putting a lot of cash into the deal then you defiantly want some protections vis a vi the seller does something wonky down the line

If the numbers work great.I recommend before you spend any money in any deal to look at the public records and make sure that the seller in the contract is the same as the deed holder in public records and what type of deed was recorded (warranty / tax).

Once I've established contact with the Owner, he/she is interested in selling, and I've done a walk-through and am still interested, would the next step be to request the pay-off amount be provided by the Owner from the lien-holder?

Been a long time since I went through process but I think you will need to this to work in US so you can be 1099ed in addition to the work Visa, and also be paid referral fees from another agent.

As for the 60 days to file a claim.....you are confusing the 60 days a lien holder has to be able to file a claim for surplus proceeds, in a tax deed auction.

If a bidder at a judicial sale (tax deed) is successful in placing the winning bid and subsequently seeks to quiet title, will that bidder take the property subject to a mortgage / lien if the relevant tax bureau fails to provide notice to the mortgagee or lien holder?  

If you are offering firsts and seconds, thirds - the 3rd mortgage holder is in a much weaker position than the first and second, obviously.