I was watching the gamespot review for Final Fantasy XIII and the host said something peculiar to me.

He said "...by the time you're free to choose any role, there's no reason to spend points in them. You end up just spending points on low level upgrades when you can use them for much more powerful enhancements"

What did he mean by that, I just wanna make sure I haven't been doing anything wrong.

Also, when I get Disc 1 and 2 back and start a new game on my Xbox Live profile I wanna make sure i'm doing everything right this time

i think he means once you get the other three roles for the characters not their main three i think he just means "by the time you get the other roles your main three roles will be so high up in level you should just concentrate on leveling those up instead of the secondary roles" like for example Lightnings three main roles are Commando, Ravenger and Medic. I think starting Chapter 11 or something like that you get the other three roles Sentanal, Sabator, and Syn (I can't remember what it's called) but you should just focus on the main three instead of leveling up the secondary ones, wait untill you have the main ones all the way leveled up before you level up the other ones, of course you won't be able to get the 10th stage of the cyrstalisum untill you beat the game

but a good way of burning up points in Gran Pulse, at some point during the story you will encounter a large wolf and behemoth fighting each other, as they are fighing each other they are easy to beat but you get loads of CP, and he respawn after walking away and coming back, ohh and before i forget, attack the behemoth first as he is the most difficult

Every character has 3 primary roles that they excell at, but much later in the game, every character is able to access every role. Problem is, other than those 3 roles they already could use, they're not good in the roles, and serve mostly as an excuse to do some trophy hunting and waste experience.

another advice to get more CP is that close to the end of Chapter 13 you will go to a place where you can fight three fights and each of them will give you 35000 CP points and thats three fights thats a lot of CP but there is an item that doubles the CP you get in battle and thats the Growth Egg but its hard to get it, you get it by doing one of the Missions on Pulse and that hunt is hard to beat