In terms of balance, you can use these guidelines to create a foundation for your CCO. These are NOT meant to be hard rules, because I want to promote some creativity. This does not mean you can go nuts and create some abomination.
Before asking for a rate, compare your CO to the motley crew of Tabitha, Brenner, Gage, Lin, Penny, Forsythe, and Will. Is your CCO going to give anyone in that group a decent fight on most maps or is your CCO going to stomp/be stomped by him or her? On that note, make sure your CCO doesn't infringe on a current CO's abilities.
Avoid situational CCOs. You don't want your CCO to be useless on 99% of the maps and possibly overpowered on other maps. Waylon and Tasha are considered two of the worst COs because of their overspecialization, and in Greyfield's case, his overspecialization BANS him on the maps he performs the best on.
This is the section where you can describe your CO's appearance and mention his biography. Pictures are optional, but they certainly help. The biography does not have to be epic, but keep it within reason. The CO's army also goes here.
Your CO's personal motto/catchphrase/etc.
This is the section where you determine the size of your CO effect. A CO zone of 2 is considered the default range since it's a nice balance between the CO effect and CO power. A CO zone of 3 is a CO that relies somewhat more on their COP while a zone smaller than 2 is a CO that relies more on a powerful CO effect than the CO power. Generally, you shouldn't exceed a CO zone of 5 fully charged unless you have a very good justification.
This is the section where you get to determine your CO's abilities. Use stars to denote increases in attack and defense. You may grant more stars depending on your CO's specialty. Generally, keep the bonuses under 5 stars or else we may run into a problem like a possible Tabitha clone.
Your COP does not have to be linked to your CO effect. However, try to keep it reasonable. Your COP can be more powerful if you have a smaller CO zone, but if you have a larger CO zone, design a power that can be used frequently because it's the main thing your CO relies on. If your CO has no COP, the CO effect will receive the bulk of the criticism.
I believe there are three quotes the game cycles through. At the very least, you ought to have one quote whenever your CCO wins.
To save the lot of you some time, here's a template.
If you impress me with your CCO, you may get recognition on the Hall of Fame. I promise the process will be faster now that I'm an editor. In addition, I'm looking for some help here as well. If you show enough activity here, you may get rewarded for your efforts.
Now, show me what you got.