Zing, your questions are easy.
The Magical Items in each Battle Pack unlock 2 PVP Arenas.
I agree they could have done a bit better with the Adventure Pack levels in Giants. They took out most of the collecting. I think it would have been cool if they developed sequel levels with the same toys in Giants. A new Adventure in Empire of Ice, Dragon's Peak, Pirate Seas, and Darklight Crypt.
Swap Force is "supposed" to have new Adventure Packs, so hang tight.
Getting money in Giants is suuuuuuuuuuper simple. It only costs time.
Get all Luck-o-Tron Bulbs and all Wealth Wheels. Epuip all 4 Wealth Wheels to the Luck-o-Tron.
Now then, go through the levels and make sure to get all 20 Winged Sapphires. AS SOON AS YOU FINISH CHAPTER 13 OR 14, go onto the crane deck of the boat, which is gotten to by going up the ramp and out of the first door, in the same room as the entrance to Auric's Shop and Dreadbeard.
On the crane deck, make sure to grab the Winged Sapphire, because not only do you want it, but you also want it so it doesn't get in the way of what I am going to tell you.
Now then, after you have that Winged Sapphire, go ahead and beat the game. After the credits roll and you're back on the ship, go back to the crane deck and you will see tons of money laying on the ground.
With all 4 Wealth Wheels equipped, you can get anywhere from 8-12k from picking up all of the loot. Now then, stand perfectly still.
If you're on Xbox 360, press the guide button (The big X in the middle of the controller) and press X to "Sign Out". You will be booted from the game, back to the Start Screen for Giants. Now then, Select Story mode, it will ask you to sign back in, do so. After that, it will ask you to select your storage device. Do so. Select your save file, and go back to the deck again. ALL OF THE MONEY IS STILL THERE! Rinse and repeat and poof, you have all the money you need at your disposal.
On the Wii version of the game, you need to press the HOME button and go back to the Wii Menu in order to do this trick. On PS3, you press the PS button and quit game. YOU NEVER QUIT THE GAME THROUGH THE GAME ITSELF OR IT WILL SAVE OVER THE MONEY YOU PICKED UP!
I got enough gold for 2 of every character in about 30 minutes tops.
DO NOT UPGRADE YOUR CHARACTERS AFTER GETTING THE GEMS, BECAUSE IT SAVES THE GAME! Get whatever money you need first and reload your save file via the method I listed above, before you buy moves...
It sounds like a lot, but it takes mere minutes.
Tell you what. I will just make a video of it and post it here, to show you how simple it is to get money.