Axis blade is gotten early and is pretty good. Increases ATB on attack, and you can stack it with Sprint Shoes for ATB recharge bonus (Which you should be using l8er n e way), along with a Whistlewind Scarf (Charges 1 lvl of ATB at the start) increases it even more. Not as much damage as some of the other weapons, but she'll be attacking far more frequently so it definatley makes up for it.
Belladona is gr8 for Vanille if you use her, and helps out a little bit if you wanna power level in Ch11.
For Fang, i'd say wait until you get the Taming Pole (The Stagger lock thing doesnt matter much as long as shes the only one with it. She can still raise the gauge, but your RAVs will usually stagger anyway. It also carries the Quick Stagger mod with a Speed Sash or Scavenger Catalog. ) Or if you plan on grinding a lot, you can level up the Pandoran spear first since you get it sooner (Helps with TP recovery for power leveling, and at Max ultimate you can dismantle for 3 Traps to upgrade the other weapons).
I'd say start out with a Power Wristband and whatever the Magic one is. Not necessary, but it helps out a little bit when your starting out. After you beat a Boss and you dont see anymore enemies, take them off so you can put them on the other chars. (Few chapters you dont get the chance, so..). You'll only need one of each, but you'll be getting upgraded versions anyway, so the choice is yours if you wanna up them or not.
Do NOT sell Tetriadic Crowns/Tiaras when you get them. Upgrade them to max, then dismantle for Hermes shoes or Sprint shoes (Upgrade Hermes to Sprint). You need 3 of these, best accesory in the game for normal battles / power leveling. (You can get Tetriadic Crowns/Tiaras on Mission 7, along with x5 Bomb cores every time, which are good for upgrading at Ch11. After you have 3 sprint shoes, you can sell the Crowns/Tiaras for a lot.)
Ch11, when you get to Oerba and kill the boss, you can start the 55 Mission before you start Ch12. Its all but impossible at your current stage, but with Vanille you can spam Death on the Peochu or whatever. (SAB/SEN/SEN). Just have an Aegisol handy, use it at the start of the fight, and spam Death. The mob should attack the SENs, right when they die, Summon and keep casting Death. Before it wears off use Gestalt and you can do some damage to the mob (Can usually kill or get them close to death). If he Screechs, just retry. Its a pain in the ass, but definatley worth it for the Growth Egg (CP x 2) as soon as you can.
Save your Clay Rings / Silstone rings and upgrade those.
Save your Witchs Wristbands (I think thats it.. adds 10% Magic Resistance. Dont need these unless your planning on doing all the missions.. like 64).
Do NOT buy Cobalites or Scarletites. You will get more then you can use l8er, and they cost too much.
Upgrade a Collectors Catalog to max and transmute it (You'll get another one of these anyway) for the other version which increases Rare Drops.
CH9 I think, if you feel the need, you can grind for some Incentive Chips in the house with the PSICOM soldiers. Run around the house and they'll respawn. Its not the best place, but if you really want to upgrade a weapon or item before you continue its the best spot at this point)
I think its a Hero Talisman, but if you upgrade it it turns into a Morale Talisman which has Auto-Bravery (Great for Fang along with a STR item)
At the start of CH11, i'd say go for the first couple of missions (Up to 14 so you can get the Chocobos), grind a little bit (All the way at the NW corner theres a save point going to the next area, a Behemoth and one of the giant Wolves fighting each other. Its always a Pre-Emp strike. Attack the Behemoth first (He'll probably transform, but it doesnt really matter.) then focus on the Wolf. If your strong enough (Or you have Fang or Sprint Shoes), set it to COM/COM/RAV. By the time the Behemoth is down to half life after he transforms, Fang will already ahve killed the wolf.). EZ 6000 CP in 30-40 seconds (Sprint shoes only make it faster). I'd say level up at least 1 of their roles here. (You can also kill this mob, then go into Mahabara, and go left at the first fork. The enemies in that corridor are easy to Pre-Em, and they're pretty weak. The bombs give good CP and drop Bomb Cores a lot. Good to add onto the Behemoth fight, then go back and they'll respawn)
Dont Max out your CP at this point, you'll be getting a lot more in Ch12 & 11. (You can keep like 500,000 when playing through these. If you get close to the Cap 999,999 I think, upgrade 1 of their lvl 0 roles. )
If you use Fang a lot and you have extra CP, go down the Synergist role. She gets Protecra/Shellra really early, and haste right after that.