Now...as for red...good work. =) But I'd reccomend ditching Kricketune in favor of Scyther when possible. I can't remember when Scyther is available, but...it's a great Pokemon. Especially if you evolve it into Scizor. Then give it Bullet Punch and Swords Dance. =D
Machop...he can be useful when used properly. I'd say Lucario is far better, but there's that issue of not getting it until the 6th Gym...=/
Geodude...do you EV Train? Try to max out its defense and special defensee. That's not easy, especially considering where you are in the game. And...er...well...I don't really know Geodude that well. I believe this is B~T's turn. =P
Scyther does a better job as a Bug Type, and does Heracross. Scyther I think is found in Route 215 (raining) and the foggy route. Heracross, you need to get Honey, and there is a 4% chance of it appearing, so it is a pain to get, but it is worth it eventually.
To evolve Scyther into Scizor, just trade your Scyther and back, holding a Metal Coat. It can be found on wild Bronzor/Bronzong and Magnemite. And if Scyther has Technician as its ability, it boosts moves that have a base power or 60 or lower 1.5x greater, so Bullet Punch will deal 40 x 1.5 = 60 Base Power. If it has Swarm, then just slap X-Scissor on it, and Bllet Punch is still an option, just that it will be less powerful.
Machop, you should be familiar with the line. It does not outclass Lucario in any way, nor does Lucario outclass Machamp. Machamp boasts higher Attack and his Defense and Special Defense, including HP, are enough to make him bulky. Lucario has higher Speed, and Attack/Special Attack, but his defenses are poor. Both are good choices, it just depends on your preference.
Geodude, you are familiar with that. I personally would prefer picking Rhyhorn in favor of Geodude. Rhyhorn is found in Route 214 (Route south of Veilstone) and Victory Road. Although Rhydon and Golem have similar stat distributions, Rhydon can evolve into a better Pokemon, if you trade Rhydon while having it hold a Protector.
In-game, don't focus too much on EV Training. Just level up your Pokemon as much as you can.
If you thought the First and Second Gyms were easy, Fantina is a far cry from "easy". Her most threatening Pokemon is... an evolution from a Johto Pokemon.
