Welcome to the forum Menashe.   I agree with your position on a verbal debate with Shapira.     Years ago Uri offered to debate Brown IN HEBREW.  Brown declined that invitation! 

We've come to the conclusion that verbal debates only add to the credibility of these posers.  Brown (and it seems Shapira, too) loves to throw out Jewish references to the Ramban, Ibn Ezra, Talmud, etc.  He generally peppers every answer with at least 3 or 4 claims to these sources.  It sounds great to a listener.   Unless the Rav debating him is a walking encyclopedia (which most Ravs are!) it is impossible to be able to quote things IN CONTEXT to show that the source is being totally distorted.  Shapira's "kosher pig" is a perfect example of how he twists and misuses those sources.

R' Blumenthal has offered to debate Michael Brown in writing for years.   He continues to decline that offer just as he declined Uri's offer all those years ago.

Did Shapira really say that היום / HaYom (the day) means eternal messiah?  How do you get נצח משיח from היום?

סופי

And everything that Sarah tells you, listen to her voice. Bereshit (Genesis) 21:12