Syria attacked and invaded Israel in 1948 along with a number of other Arab countries. Israel fought back in 1967 and took the territory. UN Resolution 242, calls for "safe and recognised boundaries free from threats or acts of force" so seeing as Syria and Israel are technically at war, Israel...
Yes, as Hamas is a terrorist group who has pledged to annihilate all the Jews and destroy Israel. Naturally Israel is going to do everything it can to protect their citizens from attack. It just means that all goods go through Israel first before being delivered to Gaza.
In other news today:
Well, not really debatable at all. Gaza is completely administered and managed by the Hamas terrorist group. Israel is no longer responsible for administering Gaza.
Israel doesn't occupy Gaza. That territory was handed over to the Arabs in 2005. Israel also doesn't occupy Judea and Samaria (not "the west bank") as all land west of the River Jordan actually belongs to Israel historically and, most importantly, legally. Even so, after the Oslo Accords, Judea...