Looking for signs of leaks is my #1 reason for annual interim inspections...I always check under sinks (taking pics) and also take pics of ceilings in general, especially bathroom and kitchens, and floors in all the suspect areas (toilet, tub, laundry, sink base, under-counter water heater, etc.) and depending on the apparent age of the unit, I try to get a look at accessible window sills if this is an issue I have any concern about.

I will reply but I doubt I will be of much help.Every state has different statutes regarding how certificates are created, acquired, effective periods, minimum certificate age required to apply for a tax deed, certificate expiration age, etc.I recommend that you post what states you are interested in purchasing certificates and hopefully individuals who have acquired certificates in these states will respond.Your strategies will dictate your operating costs. 

These are college age students, the parents often like having a house mother for their kids since they are in a foreign country.

The other benefit is the college age or just out of college kids I occasionally rent to. 

Age is nothing but a number.  

The biggest problem is at my age having access to capital, in my pocket I have several apartment deals varying from 8-16 unit buildings, all conservatively analyzed  at 12 to 17 CAP rates all less than $500,000.

Am I showing my age a little here?

How concerned should I be about the age of the structure?

., I'm gonna have to get back to you on the age of the property.

I congratulate you in your decision at a young age.