Wouldn't it be just fine if he use a sword akin to Sakabatou?
A reversed blade won't kill (if used intendly not to kill), but might still be enough to immobilize.
That's just sophistry. A sword is nothing but a tool. There are many weapons in addition to a sword, every bit as deadly, so you might as well ask why won't he use a spear if he wants to avoid the sword. In fact with training you can kill people even barehanded. The real reason is avoiding violence (solving problems by using violence). His previous life was nothing but violence, so now he wants none of it. Of course it's not going to work, but since he was broken enough mentally in his previous life, it's understandable he now wants a life 180 degrees different. Too bad the world is neither convenient nor kind enough for that.
Btw, that whole sakabatou thing was BS also in Rurouni Kenshin, and Saitou Hajime said it enough times straight into Kenshin's face. However, Kenshin was also mentally broken, so he did want he did, walking a thin line to retain his sanity, unable to accept what he was, but equally unable to leave it behind either.