If you're going to choose a smash to spam, fsmash is the way to go. I believe it really only hurts you if your opponent outranges you or is close enough to jab/tilt you before you get it off. I'd like to see less dsmash though, you have a tendency to overuse it when you're close range (I only saw the video vs Pit). It can easily be substituted for dtilt like others have said...which can then have a dsmash followed right after
I'd like to see more grabs too, I think a lot of people who play against Zelda underestimate its usability.
You kind of rely on spotdodging a lot to avoid getting hit and follow up with a smash, it's something I see a lot of Zelda's do since her smashes are usually good to go afterwards, it's really punishable/avoidable if your opponent picks up on it though.
Shielding grabbing is always an option to consider for mixing it up, especially when approached aerially since there isn't a danger of being grabbed yourself. And sometimes shield pushback is nice, since it'll sometimes space Zelda for an out of shield bair. Zelda has good out of shield options, so they're nice to keep in mind.
Nayru's was used which is good, but it was sometimes used in situations where there'd be a better move to use. It's good for covering Zelda's sides instead of dsmash, but it should be used more subtley so people won't expect it.
With that out of the way, I'd like to say I was quite fond of your platform play. Especially with those nice drop down fairs on Pit. Spacing for the most part was good as well, your Zelda is definitely on its way.