You seem to be asking several different questions. Let's address all of them in turn:
How does corruption in Israel differ from other Western democracies
Corruption is somewhat subjective but there's some well regarded efforts to measure it, however accurate they are. On such is "Corruption Perception Index".
By that metrics, in 2016, Israel was ranked #28 on the list of 176 countries, with a score of 64 of 100 (higher score or ranking means less corruption).
That definitely lags many European democracies but not all of them - France is only slightly ahead, at rank #23 with a score of 69, for example. Portugal is #29 (62 score). Spain is #41 (score 58), Greece is #60 (score 44) USA is somewhere in the middle of democracies, #18 (74 score).
For comparison, Arab middle-eastern states seem to congregate at rankings below 150 and corruption score at or below 20 of 100 (Lebanon and Iran are at 30 score), so Israel is indeed far closer to a Western Democracy average than to Arab states.
 - corruption is far harder to observe in less democratic societies. E.g. we don't really know the level of corruption in North Korea since we simply don't know details of how North Korean politics works, though we can extrapolate from similar regimes in the past. A more thorough list of criticisms of CPI is in this article.
Note: I tried other datasets than CPI but seems most (e.g. Defence corruption risk index ) exclude Israel, either specifically or because they focus on OECD.
So, does the specific # of convictions indicate bad corruption.
First off, some of your data seems like false flag data points. You make a lot of hay over "one PM and one President" being convicted. Except, of the two, one was convicted for rape, nothing to do with corruption.
More importantly, the (seemingly!) high # of convicted officials is not necessarily an indicator of higher corruption, but also better democracy, in that the corrupt officials ARE successfully prosecuted and convicted. It's called Rule of Law.
So, can I besmirch Israel as "you can't compare yourself to Western democracies" because it seems to have higher corruption?
First, because as indicated it's actually in the middle of the pack for Western democracies. Yes, far behind Nordic states's ideal non-corruption, but ahead of several Western democracies, including far ahead of Spain and Greece. And it's light years ahead of most Arab states.
Second, because corruption is not necessarily indicative of the level of democracy. E.g. Singapour is extremely non-corrupt while being a rather authoritarian state; while highly democratic Greece is lagging Israel's score by more than Israel lags all but 7 highest ranking states.
Third, as mentioned, higher # of convicted officials for corruption can actually be a sign of a healthy democracy - rule of law is paramount, and you get investigated and convicted even if you ARE a Prime Minister.