ID codes aren't encrypted, especially civilian ID codes. They can't be, otherwise no one could read them.
Military codes are eminently crackable by any great power capable of capturing the signals. Which is anyone except spics, durkas and niggers.
So your decision to attack all codes just destroyed an airplane full of allied diplomats, or an allied fighter. Your allies change sides, and you're that much further from victory.
Or you downed an airplane full of civilians belonging to a third country, they join the war on the enemy side, and you're that much further from victory. This would have happened in Ukraine if the rebels shot down a major countrys aircraft, and all because they didn't have the Buk IFF truck.
A single shot in the air costs thousands of lives on the ground.
Internal stores means all of the external stores are papered-over by stealth skin. And this skin remains in place even after the stores and fuel are expended, because its an extension of the aircraft.
Hanging stores are far more aerodynamic.
Because they're more useful, cheaper and more maneuverable for a relatively similar value in front aspect stealth - F-35 being less visible in x-band, more on infrared.
Because even they realize they'll have to bomb durkas at some point. America can't play world police forever, and Russia and China are positioning themselves to take bites out of the globe when possible.
Also have you seen their stealth aircraft? Totally outperform F-35, far more practical.
1950s called, they want their radars back.
Modern L band are LPI first of all, meaning they're difficult to impossible to detect. They're also extremely difficult to jam, 3D capable, truck mobile, and capable of resolving a target.
And by modern I mean like 1990.
radartutorial.eu/19.kartei/02.surv/karte013.en.html
almaz-antey.ru/en/catalogue/millitary_catalogue/1219/1241/1339