[Nasuno]

Gaizafaiz,

Spoiler for vol 6,7:

Yes, just like Mayushi did in some timelines.

And no, because that "timeline" turned out to be a big "simulation", just like the ones Koga Tomoe did during her arc.

At the end of the vol.9, Mai and Sakuta are still alive and kicking.

xellos2099,

Spoiler for vol.3-9:

Honestly speaking, I've read that volume quite a long time ago, so I don't remember a lot of details, but skipping a kiss or two shouldn't be a problem.
At least for me it's already set in stone that Sakata will marry Mai. (Unless author pulls some stunt, making community angry again ^^)
On this scale of things, just a single kiss is...

Also, Sakuta is powered not by kisses, but by a verbal and nonverbal abuse. ^^
This is also one of the reasons why it wouldn't be possible for Shouko-san to win
Like this: https://i.imgur.com/3iKLyf1.jpg

Btw, the other reason would be that Shouko-san is intended to be an ideal waifu, sort of yamato nadeshiko, while Mai is realistic alternative.