In general, you can say things are worn out.
What do you expect? I've been using them for the past two years. They're worn out!
For many objects, there are alternative words, but they're less general:
For your car example, I'd say dilapidated. This word works best for larger, more complex objects. A house or car can be dilapidated, but the phrases ?dilapidated keys and ?dilapidated headphones sound weird to me. You can also say a car is broken down, but only if it doesn't actually move.
For keys, I agree that rusty works, but only if they're actually rusty. If they're worn down, I'd say they're worn.
Sometimes you don't need a special word. I might complain about my broken old headphones. You could also say they're in a state of disrepair, but it doesn't sound very conversational to me.
? This symbol means "This phrase is of dubious acceptability. I suggest you avoid this phrase."
The idiomatic expression used for cases like that is bite your tongue, which means to stop yourself from saying something that might upset somebody or cause an argument, although you want to speak.
I was going to tell her the truth, but I bit my tongue.
Choke could be used if you meant to be unable to speak normally especially because of strong emotion. It would not mean somebody avoided saying something he was going to say.
Best Answer
There isn't a single antonym for "bureaucratic", because "bureaucratic" encompasses a number of ideas, although I think streamlined or possibly efficient is perhaps the closest to what you want in your case.
Other examples that you might want, depending on what aspect of the word "bureaucratic" you are contrasting include:
easy, simple, transparent, efficient, flexible, fast, direct, bespoke, personalized, streamlined, ill-defined, unprepared, undefined, undocumented, unaccountable and elected.