Tip 1: Special moves aren't the only things any character can do.
Tip 2: Smash Spam will get you eaten alive.
General tips for everyone >.>
ZSS is all about setting up attacks. Neutral B Paralyzer gun or Down Smash Paralyzer sets up for a grab which after a down throw easily combos into an aerial. Up-b will slam someone into the ground by you leading into an up-tilt, forward, tilt, Down Smash and a plethora of other things...
ZSS main kill moves are B-air, F-air, U-air, Forward-b, and Forward smash in that order.
Try to mind game people into Forward-B as its very telegraphed and not the fastest thing in the world.
As for Samus, ask TGM I'm sure he'd know far more about it then I would. I know Samus has a killer Z-air but beyond that... meh.
My Creations in Modnation Racers! Check zhem!
http://community.modnation.com/en-us/players/IvoYaridovich/creations