I'm not particularly worried about Down B. Between having to commit to a command select or cancel (which looks particularly punishable and is going to require some twitch reaction play in clutch situations), there's only a handful of times where the move pool is going to be a thing that's unable to be contested. Oomph, Psyche Up, Accelerate and Heal are the moves that most mains are going to be looking to get at any given situation given that a good chunk of the moves kind of seem like gimmicky variants of Hero's already solid set of regular moves ("Hatchet Man" basically seems to be a Warlock Punch but when is Hero ever going to go for it when his Smash attacks have random crits?).
Zoom looks like a good recovery move but RNG doesn't exactly make it one you can rely on. Bounce is only going to see use in select MUs, I can already tell Mega Man, Snake, and the Belmonts are not in a good spot. Magic Burst could pull through as a desperation move, particularly for two-framing recovering opponents, but it's going to be a risky exchange whenever the character isn't at a notably high stock or percentage advantage. Snooze's hitbox looks deceptively dangerous, I gotta admit, but at best I suspect that it's off-stage capability is only going to boil down to forcing opponents to recover high or low. Gotta admit, I can see FE Swordies hating this one.
I think what I'm more worried about is the crit frequency, and also his side special. I know Hero has a sword, but the mid-range coverage of the attack already seems to extend a generous amount. Between Zap, Frizz and any of the boost abilities from the command menu, Hero looks like a strong walling character and I kinda suspect he'll get some Olimar-level damage confirms if he plays his cards right. At the very least, it doesn't look like it'll be as braindead easy as it is to line up Olimar's formations.