It's still a good idea to do some physio for learning some exercises that help on the long run. You'll have to do them yourself from time to time and they relate to exercising the muscles that sustain the spine. Don't think "hit the gym and workout the dumbbells for 30 minutes" type of exercise, that's out of the door forever if you value whatever spine remains you have left. Essentially just the act of walking around and doing some light workout of the muscles, don't allow them to atrophy. Stupid muscles, they atrophy the moment you allow them two bits of rest and you can't afford to do that because it's them that hold everything into place.
And not all physiotherapists are born the same. Some do stupid things and may damage your injury so always exercise judgement on what they put you to do. Like I had a work colleague that suffered a knee injury while skiing and had surgery then psysio. There was this machine / apparatus that you'd strap your leg to and it would "gently" rotate it in a bicycle like pattern. Said colleague refused to be strapped to it and some time later at a demonstration the machine got out of control and started spinning "the opposite of gently" and uncontrollably. Even a regular knee would have been damaged, can't imagine what an injured one would have endured.
Generally no machines, especially when your freedom of movement is restricted and controlled by someone or worse, something else. And if it hurts, abort, abort! You're not Arnold Schwarzenegger training, it's not supposed to hurt.
Yes. I absolutely detest people who tell me "pain is weakness leaving the body" as if I solicited their advice.
I also learned things from physios on YouTube (e.g. Bob and Brad) that made a difference especially with the RSI in my hands.
My anecdotal experience doesn’t scaling with your claim. Of course, each pain is different and some just require good ol rest like you said. But that’s why you should spend the money to hire the professionals at the top of their game to tell you what is what.
This strongly depends. Some post-surgery physiotherapy at least is quite painful, and it's necessary to push through it to get the best results. Not always, of course, and your physiotherapist should be aware of what their exercises should feel like.