You gave good reasons for the IDF to be flying over another nations airspace. Reason with which I happen to agree. Tell me however, if Al Quaeda had an air force, would you feel the same about them flying over the U.S.?
Isreal may be gauging the air defenses of Lebanon-Hezzoballah.
In my view, the IDF have the same right to overfly Lebanese airspace as the United States had the right to overfly Soviet airspace with U-2 surveillance aircraft. Lebanon is a haven and refuge for Hizbollocks and other assorted terrorists groups, Lebanon is essentially a puppet state of Syria, and Syria in turn is aligned with Iran.
In other words, Israel has every right to obtain up to date intelligence data any way they have to get it, including overflying Lebanon if need be.
If the Lebanese don’t like it, screw ‘em.
The Russians and the US probed each others’ air defenses throughout the Cold War and continue to do it to this day. Just last week, someone posted a set of photos of an F-22A intercepting a Russian Bear bomber near Alaska.
The US has done the same with aircraft like from modified B-29s in the early 50s to EC-135 and EP-3E. It’s a dangerous game, since they need to fly close enough to prompt a response from the air defense system. Many American airmen have lost their lives on recon missions along the edges of Russian airspace.
The IAF did this to provoke a response from the Lebanese, and they got the intelligence they wanted. The now have a better idea of the radar capabilities, missiles and willingness to fire on Israeli targets. It’s very possible they were looking to see if Syria had based some of the newer missile systems like the S300 in Lebanon.