ZSS has the advantage in the air, which is generally a bad thing for Wario.
Most of her kicking attacks (almost all of her A moves) can be described by 'Disjointed Legs of Steel' to say the least. When she takes the time to space you generally won't beat her while you're both airborne, unless you manage to get below her.
Of course avoid the grab, she has to buffer a grab in order to grab release infinite you, and any good ZSS will know how to do this. A whiffed grab by ZSS is extremely punishable though, and should give you a very generous timeframe to get a (semi-charged) fsmash in. Resulting in death at the usual ridiculously low percentages you count on against lightweights.
Shield pressure is easy, her grab comes out at like frame 16 iirc so you can safely poke around.
Bite is less useful in this matchup because of various reasons, the most important one being that her grab outranges it.
I'm stopping now because I have to go