1. Rav Soloveichik says that the flag has kedusha because Jews died for what it represents. Regarding Rav Moshe, it is obvious to any bar data that if he thought that it was a symbol of idolatry he would not have allowed it. You are in a very serious state of denial.
2. What those sages said, they said about the anti-religious elements in Zionism. Rav Kook, on the other hand, said that they wwere Hashem’s unwitting tools.
3. Regarding Rav Teichtal’s son, that is his opinion. Others disagree.