The video shown seems like an average day on For Glory to me. Basically, and compilation of things that won't work nearly as effectively as you may think anywhere else. I feel it's important to note that most of the things that worked only did because the Ness was playing poorly, not because they were good options. It's fine as you're trying to learn the character, just don't make a habit of these things in the future. I've also noticed missed opportunities like the grab at the end could of been an up-throw, which probably would have ended the match. The best piece of advice is to do a little more research in what the moves do and work a bit on the spacing.
The one thing that I would watch out for is all those laggy landings. Remember that N-air can auto-cancel at different heights and rock-smash grants super armor. Those are probably my favorite options to use. However, if you plan on taking Zard further, you need to recognize that Zard just isn't that good when landing. If you're out of jumps, you need to respect that you're in a disadvantage so it's better to concentrate on landing safely.
How exactly to play out a match I feel is incredibly MU dependent for Zard so a clear gameplan, is a little tough to describe. However, you can watch me play a little through the replays I uploaded unlisted to my YouTube at your own leisure. I hope it helps you a little. :D (I just wished that Nintendo didn't limit this to 3:00 as I have much better examples, I was so dissapointed at this feature >.<)
Vs a random Kirby player on For Glory
Vs a random DDD on For Glory
Vs popular YouTuber StylesX2 (always great showcase playing against other Smash Bros players you know are competent as it can give great ideas :D)