I don't have a comprehensive list, but definitely make sure everything works that you can easily check, even if you don't use it often (e.g. al heated seats and steering wheel, stereo including CD player and aux in jack). Also check your rear hatch struts (Nissan calls them stays): https://www.mynissanleaf.com/viewtopic.php?f=30&t=21422.
Unfortunately, I screwed up and checked my latest replacements too late (was already past the 1 year/12K miles since last replacement). My left one leaks but right one doesn't. Oh well. I will leave it alone until they become too weak to hold the hatch open.
If you have any rattles, squeaks, knocks, clunks. buzzes or other unusual sounds, try to get them addressed.