Liens when buying foreclosure?

[Vincent Lopez]

I have a few questions related to liens and foreclosures I Texas.  Any answers or advice on direction to find answers would be greatly appreciated.

When buying a property directly from homeowner prior to foreclosure auction, do liens that are 10 years or older drop off?  

Can you negotiate with lien holders prior and should you pay off prior to closing? 

Do child support liens assigned to individual drop off like mechanics liens if the home ends up going to auction?

Thank you,

Lopez