The IDF absolutely knows that their old drone video feeds were insecure. They didn't need The Intercept to tell them that.
As for your second question, there is no actual debate about whether NSA should hoard/exploit or "fix" vulnerabilities in foreign signals intelligence. Their charter is to exploit. That's what SIGINT is.
The debate is whether NSA should be required to fix vulnerable infrastructure when that infrastructure is used by US commercial infrastructure. That's not what's happening here.
So since they knew, there is no harm? Your second point seems to miss that whatever the foreigners are using may be a popular choice for naturals as well.
(Notice the US selling F-16 abroad only to then having to break their video stream. At least the British don't sell missiles that they can't deactivate when coming their way)
As for your second question, there is no actual debate about whether NSA should hoard/exploit or "fix" vulnerabilities in foreign signals intelligence. Their charter is to exploit. That's what SIGINT is.
The debate is whether NSA should be required to fix vulnerable infrastructure when that infrastructure is used by US commercial infrastructure. That's not what's happening here.