The current situation is like somebody commits a murder. Then the community rounds up a posse and goes out to kill the murderer. Then kill the murder's family, their neighbors, the residents of the next neighborhood over, raze the neighborhoods and then take all the land for themselves.
Justice means penalizing the guilty parties, not everyone in their geographical/social group. Your definition of Justice is leaky.
A singular terrorist event is not the same as an multi-decade occupation, on-going theft of land, discrimination, annexation plans, and - not least - a 2 year long genocide of tens of thousands of civilians.
So, no, that isn't what Hamas did.
And how could you oppose both the occupation and annexation plans? Annexation is an end to occupation, no? I also think that the occupation has been going on for far too long, though I fault UNRWA and the PA for that as much as I fault Israel.
Taking both together, nothing you've said justifies what has taken place over the last 2 years.
And your comment on annexation as an end to occupation was truly bizarre, but ... unsurprising at this stage.
By your logic most of what happened in 1944 and 1945 when 350 000 to 500 000 German civilians died were probably injustice.
But in the real world we need to deal with the people who again and again attack their neighbors in vicious ways.
And we need to finish it.