You keep using a lot of extrenuous situations
I hope you meant "extraneous", otherwise I don't get your meaning. In the world of battling where OU monsters run everywhere, most situations are quite applicable, since you will run into a monsters that follow that methodology in their move-sets.
Of course Zam is near useless gainst darks
Often, HP Water is standard to face Tyranitar and Houndoom. Going on.
is there a single dark type you can catch in game? Not a one.
Every version has Dark types to catch. R/S has Absol, and F/L has Houndoom, for example.
So the only way your opponent could get anything that is truly strong is if they go to ghost tower, and the ghosts you get are jsut as weak to Zam as zam is to them, or get it from Ruby or sapphire.
If you're just playing in-game, then Recover is more useful. This looks to be the case by your reference to Lavendar Town's tower. Better to Recover than use a potion.
NOt to sound rude, but I asked for suggested replacement moves for Trick, not for a lecutre on Alakazam's usefulness.
Not to sound rude, but I don't take it lightly when someone tells me I'm incorrect when I'm in the right. Recover is useless more often than not in competetive battling. It's very iffy to put it on Zam, and it's very dependant upon the role it plays in a team -- kholdshire's Zam, for example.
You asked for a replacement for Trick, here's one: one of the elemental punches that works for you. If you're lacking a Fire-type attack on the team, use Fire Punch. Thunderpunch, I believe, has the least resistant types when used with Psychic, so I suggest that if there isn't an attack type lacking on your team.
If that Zam works well for you, then good for you. In my opinion, it's more important to use move-sets that cover as wide a range of possible opponents as possible. Still, good for you.
Edit: I was in and out writing this post, so I missed your post, Toothache. Delete this post if you want, but I'd rather leave it as is.