Oh! going into a foreign country with an attack helo and murdering people is not an act of war? That is a retarded statement.
Not against Hezbollah. Hezbollah is not a country but rather a militant organization banned (from being armed) by UN SC resolutions.
If Assad wants to consider it an act of war and violation of Syrian sovereignty he could (as would all the strikes from Syria on Israel).
As for Shebaa farms area, the UN has placed it under Israeli control for now. When Israel withdrew from Lebanon the UN certified that it had done so. Of course the fact that the area was part of the Syrian Golan.
More importantly, the only group entitled to contest Israel's authority over the region would be the Lebanese government and army, not the bunch of hezbollah thugs.
And as for stats, 750,000 Arabs people fled Israel (and 800,000 Arab Jews fled to Israel). Even if you want to ignore the UN Convention on Refugees and extend status to (male) descendents there are still far far fewer Palestinian 'refugees' created in 60 years than there are Syrian refugees created in the past 5 years. Of course only one group gets your support while the other you consider ISIS terrorists.