They'll see zororak in the preview undisguised, so they'll be aware of it for the whole match. With the partners you've mentioned so far, delphfox would be best to pose, there are other options out there such as gengar, who would be a good partner to try with zororak since they can cover each other's weaknesses and they both use focus blast.
As for zoro and flygon being a common pokemon, I really can't give an opinion on that I'm afraid, since I don't play battle spot or games with VGC ruleset.
But as for the set, don't worry about status since it won't give you away nor does zoro has the bulk to withstand a single attack in most cases. Items you should be considering is either a focus sash or you could swap out nasty plot with trick and use a choice specs set and trick has a nice benefit of shutting down defensive threats that could wall your team or you could give it to something that wouldn't want it (though, use this with caution and avoid giving it to a pokemon that won't mind it). The current moveset looks to be fine at the moment, I wouldn't change it at all unless you are going for choice specs.
ty for the info Great Horned Owl. id rather go the focus band route for better chances, and leave choice specs out of it. in HG I triggered a focus band on an opponent 4 times..... im not much into locking into a move. a buneary?? did switcheroo to me in HG battle zone and that Flygon was stuck with dragon claw??. it wasn't easy but I got past it.
my flygon is admant with e-quake, rockslide, dragon claw and crunch. crunch is useful on certain occasions but the other 3 are the mainstay attacks. rockslide actually saved me in my battle as the lapras survived 1 rockslide but flinched to lose the fight. I regularly lose in speed to that cursed purugly or faster pkmn. its more of a struggle to target steel or ghost/psychic crunch or a fire attack though no spa EVs were distributed (skarmory/ forteress)
I don't really follow certain rules but put those which ring a cord with me. im known to use sub par pkmn in game (offline) ie HG battle frontier-flygon, dewgong (hydration), raikou