Okay, let's play this out to make sure I understand you. Israel ends the occupation AND lifts the blockade (two different things). The next day Hamas fires an indiscriminate rocket towards Israel. Israel can now act in self-defense, yes?
What sorts of things can Israel do in self-defense? Can they enact a sea blockade? Can they restrict the movement of items which can be used for military purposes? Can they restrict luxury items as a deterrent? Can they be relieved of a duty to provide commodities such as water, fuel, and electricity? Can they refuse to enter into trade relations? Can they restrict entry? Can they conduct a house-to-house ground invasion targeting military personnel and objectives? Can they utilize air strikes? Can they occupy Gaza (in the true sense of the word, meaning Israeli administrative control)?
I'm trying to get a sense of whether your issue with Israel's actions is more "the people of Gaza will have no quarrel with Israel, and will therefore give Israel no cause to have to defend themselves, if only the blockade would end" OR if your issue with Israel's actions is more "self-defense can never include these things".
I think your argument is inconsistent either way. I'm looking for clarification on which of these two things I should pursue in this conversation.