Essentially, have you tried everything to make the properties perform better?

You are heavily dependent on management to perform.

And past performance of the tenants. 

Such as, “Find addresses for all the little old blue-hair ladies in Arkansas.”2.Perform the task yourself, preserving each step, each link, each phone number (although, I have yet to ask VA’s to use phones.)

I haven't identified a new house or area yet, but like the way my almost 13 year old rental has performed because it was new when purchased. 

Making sure the 6 P's are in order (Proper Planning Prevents Piss Poor Performance) First off, there is nothing wrong with being educated before you do something.

Performing Notes - The greatest stratgies for this if it is a performing note and they pay on time is to hold it and collect compound interest.Otherwise there are numerous companies looking to buy seasoned notes of two years or more that have an excellent payment history and good credit.Non-Performing NotesWhich are my favorite.

Aside from that, Feb-27 is contract expiry.Shall I hire a lawyer to ensure that seller performs on the contract?

We end up performing resarch on approximately 200 of those properties.

Tax sales investing is definitely a complicated industry to get into, but there are some resources coming that will immensely reduce the time and cost to perform your research.