Even if that’s true, I can’t blame Gazans for refusing to become slaves.

The OP said "destruction of Hamas and disarmament of Gaza" would suffice. Does that necessarily entail slavery?

Nothing is certain, but it seems likely since Palestinians in the West Bank don’t have basic freedoms either despite no Hamas presence.

Why would the israelis prefer to deal with PIJ through some temporary disarmament?

Anyone who listens for a bit to israeli mass media will soon be convinced that anything but the extermination of the palestinians is not enough. This is why they bulldoze everything archeological that does not play into zionist myth making. This is also why apartheid is common in local politics in Israel, and why the zionist guerillas and later IDF systematically destroyed the homes and property of the people they displaced, long before the appearance of Hamas.

As I usually do, I'd also like to remind that the zionist movement is mainly a movement of christians.