Your question without all the rhetoric is: Does self defence justify elimination of an entire nation, country, ethnicity or people? The simple answer is no. Elimination of a nation, country, people or ethnicity is the textbook definition of genocide. If you read the article, you would know that ICC is charging hamas for war crimes as well as the Israeli regime, because war crimes by one party do not justify war crimes by the other party. So you do not need to think where the line should be drawn. The line already exists and Israeli regime has crossed it.