You can publicly search taxes through the county but they will not notify you if the customer hasn't paid.Remember to make your note official; have it in writing, signed and notarized by all parties, filed with the county, and place on the title of the home.  

(If I get the POA form, do you know  if I can network for a private notary here to notarize for u.s. citizens, or must I, (all u.s. citizens) have to take all forms to the U.S. consulate?)

If the seller will not do the work, you will need to sign a notarized document at closing promising to do the work.  

I just wanted to add that some states render leases longer than one year unenforceable and some only allow them if they are notarized.

So make sure you have every 'I' dotted and 'T' crossed (if you are the listing agent that means that you need a drivers license, copy of the listing agreement and perhaps a notarized letter from the seller).I'm surprised that with a complete rehab needed, you didn't have the buyer be responsible for the CO.

does it need to be legaly notarized?

(Make sure you have a good portion of the rent applying to the purchase, lock the price now, try to get five years to accept the option with a built in extension, record your agreement, do title and lien report (you need to know what is in the chain of title and liens, all owners must sign, get agreement notarized, option should be fully assignable, if the house needs repairs, get 3 months free rent, be sure of the present value and calculate value after five years and deduct your rent credit).Get some expired listings in the area you want to live, contact the sellers and make them an offer based in the ad above.

If not, are you willing to give up 50% of your equity for the $30K in rehab money? 

Unless you have something in writing notarized and certified then it has no teeth to it.If the city wants the land they could perform an abuse of power with a higher use buyer wanting to go in and make it difficult for them.

Have the letter notarized & certified mail (You'll need this to show the judge)2.