@nebulon just for information - livepatch doesn't mean you don't have to reboot - it just lets you postpone that moment as convenient.
For sync - a good practice on old good *nix is to issue sync twice before reboot - to make sure the buffers dumped for sure.
On the reboot automation using third-party apps - it's doable; everything is, but why, if you can just add it inside of the system?