They had a budget surplus of less than $5b least year, so that money still makes a difference. Not sure if it's just the usual $5b either right now, I didn't go digging hard for it, but the data I saw for for much aid the US sends Israel was from before Oct.
US government gives $5b to various US weapons manufacturers who then send weapons to Israel, who then has weapons without needing to spend their own budget money on them, saving $5b.
They might. There's peace because attacking is too dangerous (what they have now, at least with the nations not attacking them) vs peace because treaties are in place vs peace because no one wants to attack them. That middle one is risky because situations can change fast.
And there's another angle that questions whether they wouldn't need weapons during peace for less generous reasons.
So in the ideal scenario where there is lasting peace with open borders and open trade... Why would Israel need funding? If anything the whole region would benefit from this I don't understand why people think that the country NEEDS instability. They are doing well off as is with these problems and I would bet everything I would ever own that lasting peace would make their situation even more profitable.