This would be a long process

Definitely agree with finding the lawyer specializing in the area

-City of Houston could be liable as the City had to issue the pass for the foundation before the construction of the frame

-your builder will sue its sub-contractors 

-was the tree root debris remover hired by the builder?  I would not contact any 3rd party to rectify any issues unless they are done by the builder - evidence of the builder's liability

-builders always buy their own insurance

-have you ever contact your own property insurance?  I would ask the lawyer how to approach the insurance

-google on-line related articles so you know what to expect and what questions to ask and not to ask