Texas Tax Auction Newbie Questions

[Allison Edwards McDade]

I am learning as much as I can about Tax sales and recently found a property that was in a good area to rent. I am new to real estate in general but I have a few specific answers I am trying to get answered:

1) If there is a mechanic lien on the home, what options does one have in getting rid of it? Can I negotiate it down? 

2)If there is a child support lien, are there any options to get that removed or do you just have to pay it if you want the property. 

3) best ways to search for mechanic liens? I talked with the harris county clerk and they told me that leans will pop up out of nowhere after a property sells at auction. 

I just want to be informed and have the best possible experience when I do take the plunge.