Re: I think I'm feeling burnout or worse. I am seriously considering walking away.
Man, I feel compelled to say something but I really don't have much to stand on ...
Basically I'd say that our training is our own responsibility. I too longed for the rough and tumble but when it came to it I really was biting off more than I could chew but was not secure enough in my own belief in myself to acknowledge my limit and back away and ratchet down the intensity so I ended up permanently injured. I was young, strong and eager but now I'm old, strong, eager and broken.
I fault no one but myself (at the time I certainly was ready to blame others).
I'd also say that 4th kyu is way too early to be put through what you have described. 'Grooming' up to yudansha to enable the level of training and exploration that from the outside looks to be abuse plain and simple is one thing but jumping straight into it for mudansha is not the way. I use 'grooming' purposely as it is a loaded word. To wax metaphorical one can build much more from soft clay that can be fired into solidity than simply starting with a chunk of granite and chipping away to see what is left. One method builds while the other destroys.
To really go out on a limb I'd also say that I don't recall mention that the founder ever insisting anyone do anything. He trained himself and others followed. If they could not keep up they were left to their own devices. I try to keep up with my sensei but I fail. I still do my best and do make progress. Others do more and others do less but we all progress together.
In my own case the worst patch was after 3rd kyu because I was really self deluded and believed the fantasy. I got better eventually, mostly. These days when the overly eager 3+ kyus come around I point out to them that the correct form is more important than whatever it is they are able to perform and they really need to slow down and dial back the power to find the correct form otherwise they will be going backwards. Some listen, others I liberally apply reversal (or just stop them) to demonstrate the weakness of their efforts.Right or wrong, at least I hope to have helped prevent them repeating my mistakes.