After playing through the entirety of the most recent version of the hack, here are all my suggestions and complaints:
General Suggestions:
The gym leaders level up too quickly, while the wild Pokémon level up too slowly, with the regular trainer battles in between. It's pretty unbalanced that way.
There should be more trainers and/or more grass that is required to be walked through in the later routes.
There sould be something like a flashlight key item to replace the Flash HM, as Squirtle's Cave (and any future dark caves) is very annoying otherwise.
Give us the option to buy or find Everstones somewhere early so I don't to nearly constatly cancel evolutions.
Link Saffron City back up with Vermillion and Cerulean like in the games. Just because Ash never did it doesn't mean you should deny us the ability to backtrack further back than the Ghost of Maiden's Peak episode. Besides, how are we supposed to access the extra areas behind the cuttable trees back there otherwise?
There are several spelling, punctuation, and grammar errors that need fixing.
Specific Suggestions:
If you don't want us to select the female trainer, then can't you find a way to keep us from doing so?
Brock's Onix and Jessie's Ekans/Arbok need to know Dig. They may not ever call it by name, but it's clear what they're doing when they say something like "Go underground."
Why can't Charmander learn Metal Claw like he can in the real FireRed game? No, Ash's Charmander/meleon/izard never used it, and it couldn't learn it in R/B, but Ash's Pikachu has never used Double Team or Slam, which it also couldn't learn by level up in R/B, and you (pretty much) left its moveset alone. Why would you bother to switch Charmander's moveset over to R/S/E when there's no story-driven reason to do so?
On the same note, I understand how the story made it necessary to switch the levels that Pikachu learns Agility and Double Team, but why was Butterfree's Confusion pushed all the way down to Psybeam's spot, while I have no idea when it will learn Psybeam? If you were worried about us beating Brock too easily with Butterfree's Confusion, couldn't you just stick in at something like L16 instead of making us wait all the way until L34 while keeping Psybeam at L34?
I'd like to see a battle against Meowth after the initial Team Rocket double battle in the Viridian Forest ("Ash Catches a Pokémon"), as that's one of the few times that he actually tries to battle
Shouldn't Samurai apologize after you beat Beedrill and save Metapod?
Ash's Butterfree should be a boy. You even made it a boy when we trade Raticate back for it, so why is it a girl when you first catch it as Caterpie
In "Path to the Pokémon League," "seven" in Spanish should be "siete," not "sieta."
There are only 5 Squirtle in the Squirtle Squad, not 6.
Sabrina (the second time) in particular is really overpowered. Can't you tone down her Kadabra some?
Fuschia Gym is annoying in that you changed the invisible wall layout but left the little marks on the floor (that tell you where the walls are in the real game) unchanged. Can you move them to the correct positions or at least take them out?
By the way, I can barely understand the Fuschia Gym riddle even after learning the answer. I bet you could phrase a little better without making it too easy.
Why doesn't Pidgeotto come out with the others in "Snow Way Out" and "The Purr-fect Hero?" If it needs to be an event Pokémon to use it that way, then just modify the Viridian Forest encounter with Pidgeotto to be an event capture.
As I mentioned before, there's a huge bug in "March of the Exeggutor Squad" where you can't get in the tent if watch the cutscene where the assistant quits and then go battle everyone at the circus before coming back to the tent.
I know there's not supposed to be a Pokémon Center close by in "A Chansey Operation," but can't you at least put one in Neon Town (which still isn't that close to the aformentioned episode), so we don't have to make a huge backtrack before I can grab the Togepi egg, not to mention how annyoing it is to travel that far through that many episodes without being able to heal at a Pokémon Center?
Meowth need to be a lot more common to find in "The Purr-fect Hero."