Welcome to Gaia! ::

Well, based on the outline you have here, I don't see anything particularly wrong with the way this team is set up; you have a fair type balance, your attackers should cover most pokemon on both the physical and special sides, your tanks should be able to do their jobs well, and that is an awesome custom trainer sprite.

All that being said, there's nothing I can suggest beyond outright replacing pokemon. If I had more info, I would try to give more advice.

As far as replacing pokemon goes: Umbreon is a better tank than Espeon. Alakazam is a better tank AND sweeper than Espeon. Fearow, Dodrio, and Swellow are better sweepers than Pigeot, while Altaria is a better tank. Gyarados does everything Feraligatr can do, only better. Jolteon, Ampharos, Raichu, Lanturn, well...just about any fully evolved electric pokemon is better at zapping things than Luxray. Roserade and Leafeon are better at Special and Physical respectively than Sceptile, and Exeggutor beats all three given weather support. The only pokemon that fills a unique niche that isn't outdone by someone else is Infernape, and an argument could be made that Blaziken hits harder at the price of speed.

Now that the giant block of text is out of the way we can get to your question. Yes, chimchar will evolve into Infernape once you remove the everstone...in a manner of speaking. A pokemon needs to level up in order to evolve, and chimchar needs to evolve twice. So removing the stone at lvl 67 will get you a lvl 69 Infernape if you continue to train it.