We agree that "Does Israel have a right to exist" is the stupidest question. The best response, though, was from Natasha Hausdorff, who said (paraphrased because I can't find a short clip), "Israel exists. Demanding it be dismantled isn't akin to preventing a pregnancy, it is akin to murdering a man in his 70s". Natasha is a brilliant international legal expert and recently offered to debate international law with Francesca. Francesca declined. Shame, that. It would have been epic.
The framing Francesca gives, does leave her position on slippery ground, though. Because Palestine is NOT a State. And can't yet be a State because it does not fulfill the requirements of a State.
The term "occupation" refers to territory, not to a people. A "people" are not occupied, territory is occupied. Since there is no territory belonging to a State of Palestine, there can be no occupation.
There are only two legal ways forward: 1. Arabs negotiate a border agreement with Israel and secede. 2. Arabs accept Israeli sovereignty over the whole of the territory.