Typically because the land is already purchased the rent to cost is very good on an ADU compared to purchasing a new property.  

Zillow, Trulia and such gives some information but frequently its not sufficient (ie Too few comparable home sold within the 0.5 mile radius or even the same zip code). 

I am comfortable with the property I am buying, I reviewed the records at the county recorder's office.My question was whether anyone has had issues with prior liens after receiving a tax deed.

Generally Texas has not seen a terrible real estate downturn since the 1980s.  2008=2010 was mild as compared to the nation, but the next downturn in Texas is going to hurt.

Should I do this immediately prior to sending the earnest money, or should I send the earnest money, wait a couple of weeks and then do it?

The existing lease was made by us prior to the new standard lease which has to be used now.Can i add the person to the old lease?

It looks at your initial cash investment and compare it to cash received at specific time.

Prior to me putting my property in a trust I would file my own evictions.

When looking for hard money lenders I would suggest to do your research, and definitely compare their rates and terms to others.

Given that her lease expires at the end of July '18, I want to get something signed stating that she will move if another tenant is qualified and moves in prior to the end of her lease.