There seem to be a couple of different points of contention here, and I'll try to address them both, giving my own view.
Zionism, as a political stance, is the belief in the continued existence of Israel as a Jewish and Democratic State. (If this phrase sounds familiar, it can be found in Israel's quasi-Constitution and significantly shapes public debate and Constitutional jurisprudence.) This view is an extremely broad one, and for that reason it is held by people from all across the Israeli political spectrum. In terms of the Israeli-Palestinian conflict, some of those people (with whom I personally very strongly disagree) also believe that Israel should assert sovereignty over the West Bank and expel its Palestinian population, while others support the immediate dismantling of all settlements, a complete exit from the West Bank and a final status agreement with the PA. The latter group is actually a lot larger than the former, and it represents the entire left-of-centre part of the spectrum. Even Likud (in theory, at least) supports it.
There is nothing wrong or immoral with Zionism by itself. It is simply a stance which supports the right for the Jewish people to a State of their own. Nationalism. Nothing special.
The second point of contention is whether the IDF targets civilians, and/or whether it is guilty of war crimes.
If the IDF systematically targets civilians, it is doing a terrible job at it. That one of the most advanced armies in the world would completely fail in such a simple mission is outright ridiculous.
In fact, for fighting in such a densely-populated area, the ratio of civilian to militant casualties has been extremely low in recent rounds of escalation. Have you checked the number of civilian casualties in Vietnam? The Gulf War? Afghanistan? Iraq? Not only are they much higher than the number of civilian Palestinian casualties, but they are also proportionally much higher when compared to militant casualties.
Have mistakes been made? Absolutely. Have civilians died when they should not have? Yeah. But this can be said about every single war Australia participated in in the 20th century. Should we be criticising the ADF instead? I've never seen the same level of scrutiny as applied to the IDF being applied to any other military in the world.