I have no problems with comic relief, but if it starts to get in the way of story development, it gets dubious.

But I suppose Sanji was always useless in front of women, so maybe this isn't actually any change at all, aside from his very life supposedly being in danger. Though if I was asked to donate blood to a guy who bleeds it merely from being touched by a woman, I'd refuse without a second thought - unless serious money was involved. Do these guys even have any money?