To add to miltankRancher, there's some alternative sets you can go with on the Pokemon.
Wish is generally in most of Vaporeon's sets, though you can make-do with toxic / protect, which basically takes advantage of its stalling abilities rather than use it offensively, 'cause pretty much while you don't have wish, you can still make use of it since it generally lasts long in battle. The set you had wouldn't really help it, since you don't need two water-type attacks, even if they have a different purpose. Bite doesn't really help it since it's weak and doesn't counter anything it'd be affected by anyway, and aurora beam is weaker than ice beam. But yeah, I'd go surf/ice beam/protect/toxic, since ice beam is for the things that aren't affected by surf, and surf being your STAB, while the other two take advantage of being able to stall the opponent.
Mr. Mime was generally used as a not-entirely-offensive Pokemon, utilising either baton pass or trick, allowing it to help out its team mates. However, since you're going partially offensive, as Miltank Rancher said, Psychic > Psybeam. Thunderbolt is also better than Shock Wave, and Double Team doesn't really help since it lowers the opponents evasion, rather than increase your stats, the latter of which you'd want to do. For this reason, back in that generation it used attacks such as Calm Mind & Meditate. Basically if you give it CM it can improve its STAB as well as improve its other attacks, if not, go with the actual set, being meditate & brick break, which fits in with psychic. Magical Leaf also doesn't really help it, so it is something you could replace.
On pidgeot, generally yeah, lowering oppnents stats, aka sand attack doesn't really help, instead go for something with priority, aka quick attack so you can outspeed when switching in for the kill. While it can learn steel wing, it doesn't really need it. Also, yeah, Return is good due to it being its STAB.
For Venusaur, Frenzy Plant isn't really a good idea, since while it's "good" you can't move on the next turn and you don't really want to risk that. Toxic can work, but you'd rather be annoying with leech seed + sleep powder, but since you can't really learn hidden power as it otherwise would learn here, just go with leech seed > cut and leave it as is, imo. But yeah, agreed with giga drain, though, due to no physical/special split.
On electabuzz, just mentioning that thunderpunch AND thunder aren't a good idea - mainly because thunder has bad accuracy and you don't really need two electric-type attacks. :x
Aaand for Hitmonlee, since Mind Reader and HJK can work, you don't really need brick break. Since it basically takes two turns to set this up, then earthquake and rock slide can work for coverage that you otherwise wouldn't receive from the two attacks. Be cautious, though, setting up this two turn thing can be dangerous, so Brick Break is really preferred, buuut up to you.
Good luck!
