Provided you have a quiet upper body, then I can't really see how wider bars are going to make steering more sensitive, Parkinson's disease excepted. Re narrower bars, my suspicion is that low trail enables one to still have "responsive" (aka twitchy) handling whilst needing less leverage for countersteering, i.e. if you like that sort of handling narrower bars won't impede it much. One could also argue that wider bars increase stability at low speeds off-road as the forces generated from hitting rocks, roots, etc, are more easily resisted with them.
IMHO, bar width should be chosen to suit personal ergonomics, not because it's trendy or Person X likes or recommends it.
Later,
Stephen