A few things:
1) To the point of bad faith
a) Why is "cutting plant leaves is obviously nothing like cutting animal limbs"? Is it because animals can't regrow limbs and plants can? Doesn't that lead you down the road of 'torture is an animal-based concept and you can't torture plants'?
b)'Plants routinely stay juvenile their whole life' precisely because they are deprived light, frozen outside, or lack access to water. Sometimes humans do that, WAY more often it just happens because of where a plant is rooted. And to be clear, bonsai does NONE of those things, the point of bonsai is to keep the plant alive as long as possible!
c) Do you suggest that bacteria can be mistreated? Why is bonsai torture and hand sanitizer is not? Pivoting to fungus, do you realize what we do to yeast in order to make bread/beer? Is that torture? And before you make an exception for food, we do not need beer to survive.
2) >some plants are clearly individuals with their own habits and preferences.
>why you're going on about anthropomorphizing plants (especially when I didn't talk about humans at all).
Maybe you have a very loose definition of 'individual,' but I think you forgot what you wrote.