No it does not.
Schiff has proven himself to be incredibly corrupt. He made up his own version of the phone call and only admitted to it when he was called out outside of congress, selectively leaked info to the press, refused to even allow certain lines of questioning, lied about not knowing the whistleblower after it came out his staff worked with the WB full 12 weeks before this whole thing started, and is now spying on republican lawmakers and conservative reporters.
There is no reason I can think to cooperate with him. He is running a kangaroo court that already determined the verdict. Anything Trump would have done would have been spun by Schiff regardless of how innocent it was.
Provide a fair arbitrator and you'll have a different opinion from me, but Schiff was far from fair. He residing over the hearings help a lot with half the country becoming disillusioned with the inquir.
What does that have to do with anything?
He could be the devil himself, he will still ask questions and get answers from people under oath. And these answers will confirm that Trump did or didn't do what he is accused of (we already have at least one clear testimony that he did...).
Refusing to testify conveys the clear message that you have something to hide.
You realize that, by your logic, a president will never get impeached right? Since the process is by definition led by the party not being in office, you will always claim it is political (I assume whether it' a Republican or Democrat president being accused)... and this claim will always push you to refuse to testify, rendering the current impeachment process (defined by Republicans... you've got to love the irony) useless. Which is unconstitutional because the great founders have clearly made ground for the possibility of an impeachment.
You claim you love logic, I hope that you will have the honesty with yourself, if not with me, to acknowledge that you are caught in circular thinking.
Cheers,
Bernard