My understanding is that if you acquire the deed to a property through a tax sale that you are required to inform any and all heirs/owners of the property in writing (and possibly receive some sort of receipt of such), and if you miss one heir or owner then they can come back years later and claim ownership of the property.Can someone shed some light on this type of transaction, specifically what are the risks involved in such a transaction? 

It could kill the transaction, yes.

There after make at least 12 transactions my first year with my mentor and save up to buy a duplex or a small multi unit.

Here is where we are: I've talked to one broker recommended here and Wells Fargo, provided the same info to both: our credit score is 800, and both of us employed for over 10 yrs.  15 yr loan of around $390k, signed contract tomorrow or Monday.  

You just took a giant leap in the right direction; signing up on Bigger Pockets!

You can also call the number on those "We Buy Houses" signs and tell them that you would like to help with their marketing. 

They always offer 0% interest rate for 12 to 18 months, but I need to pay 3% transaction fee, for 12 to 18 months, which is still good rate.

Owned 6 rental properties in Hays, Kansas, a small college town....we always started advertising our rentals the day after St Patrick's Day and would make the students sign a one year lease..you basically have until school starts to rent it out with the more responsible students signing earlier.

The only way to get it done these days is to sign up for all the REO sites (Xome, Equator, HomePath, Res.net) and wait unless you know someone who can get you into some of the larger scale REO events to network with the asset managers.

I've had many transactions where I received pro rated rent and security deposits from the seller.