Hi there, let me take a crack at this :) :
1) If I understood you correctly, I think you wanted to say "The identities of the seller/vendor and the witnesses have been verified."
2) "He goes to the school" means that he attends at a specific school. Your sentence therefore is incomplete because it doesn't state which school he goes to.
"He goes to school" simply refers to what he does for a living, namely that he is a student and goes to a school to study.
3) In fact you can use "to" in front of the word "home", but to do so, you need to include some kind of an indefinite or a definite artcle before "home": "He goes back to his home...", "He comes to my home...".
4) "He held me up to ridicule me" - Technically, it's a correct sentence but it does not have the meaning that you intended, and it also sounds rather awkward. "He held me up..." means he stopped you to ridicule you. There's also no indication from the sentence that the ridiculing took place in public.
Your "he made fun of me in public" is much better in my opinion.
Student or Learner