Is it OK for some Israelis to do genocide against Palestinians if some Palestinians tried to do genocide against Israelis? IMO no, there is no justification for anyone to do genocide.
There was a plan in ~2016 backed by Zuckerberg, Hawking and some entrepreneur but it didn't really get anywhere (in a literal sense). Research for it stopped in 2022 because of a "lack of funding".
I'm a from england where we don't have mass shootings an this seems so fucked up to me, I'm so sorry for you that must be terrible even to be close to that. I've heard of shootings in america but this description just makes it so real.