Falkner should definitely have something other than the generic Pidgey. A Natu and/or a Hoothoot would be nice. Both or Generation II Pokemon.
As for Bugsy, he should have evolved both his cocoons. I mean, geez, the last trainer you battle in his Gym before him had a Beedrill, while he had a Kakuna and a Metapod
He should go for a Butterfree and a Beedrill, but that would make his team have all Kanto Pokemon.
Otherwise, he should go for a Ledian and an Ariados, much better alternatives I I do say so myself XD
Whitney needs something more than a Clefairy and a Miltank. How about a Granbull, a Togetic, a Smeargle or even a Tauros? Granbull's a good bet, it had Intimidate. Togetic can be a somewhat her special attacker. Smeargle has any move, so that's almost too overpowered, and Tauros so Miltank won't get lonely, if you guys know what I mean
Morty is already generic as he is. Good riddance to Gastly and one Haunter and hello Misdreavus. That's the best bet so far
Chuck needs a Heracross or a Machoke. Seeing as how Chuck is muscly and he squishes bugs for breakfast, I think he would go for a Machoke. Otherwise, he'll go for Heracross XD
No more 2 Magnemite for Jasmine, hopefully. She needs a Forretress and a Skarmory. Seriously. And one Magnemite becomes a Magneton
Pryce could go for a Sneasel and a Lapras. One Seel will be kicked out, so he'll have Sneasel, Dewgong, Lapras and Piloswine, in that order.
Clair is BS. She should kick out one Dragonair, and put in a Gyarados. One of her Dragonair would be physical and her other be special. Kingdra should stay, definitely.
Will should remove one Xatu and replace it with an Espeon or something
Koga should remove the Forretress. It wasn't a Poison-type, jeevers...he should get a Weezing instead XD
Karen needs to let go of the Vileplume and the Gengar, she's a Dark-type user for crying out loud. Should definitely have a Sneasel and a Tyranitar, IMO.
Lance should have a team like this: Gyarados, Aerodactyl, Charizard, Dragonite, (insert final evolution of an Elm starter her), Dragonite. Otherwise, he could just get a Kingdra for the other Dragonite. Just because two well-known NPCs in the game have one same Pokemon doesn't mean it's wrong. It's just a Pokemon for crying out loud -________-
Well, that's criticism for yeah, or something XD