Modifying someone else's type 1 systems is the sin. Improving one's own (typically by identifying things with type 2 and reinforcing them to make them smoother in type 1) is mostly good.
Rhetoric is other-directed: how to "win" a debate. There are elements of truth-seeking in there, especially if done with steelmanning and rigorous humility. But that's rarely where it comes from, or goes.
CFAR did a lot of work in helping people align their type 1 and type 2 which I wouldn't call sinful but is about modifying people's system 1.
We acknowledge that sometimes type1 solutions are better that type2 solutions and the only way to change type1 processes is with rhetoric.
No, I don't acknowledge that the only way to change type1 processes is with rhetoric. There's a variety of verbal and non-verbal processes that can change type1 processes. When it comes to a process like Focusing that does mangage to change type1 processes that does have a verbal component calling it rhetoric still seems misleading.
and the only way to change type1 processes is with rhetoric
Type 2 processes are implemented on top of Type 1 processes, so anything that affects Type 2 processes also affects Type 1 processes.
We acknowledge that sometimes type1 solutions are better that type2 solutions and the only way to change type1 processes is with rhetoric. But improving type1 systems is a cardinal sin.