Hold L + R and press A + B + X + Y at the "Press Start" screen. Then, press Start. All items in the WWE Shopzone will be unlocked and will remain that way until you play a match. Also, all arenas and legends will be unlocked for one match. The code can be repeated to unlock them again.
Reach Amateur status to get $100,000. Reach Rising Star status to get $100,000. Reach Superstar status to get $300,000. For $500,00, complete all the legend tasks under the legend difficulty setting. With most of them you can use two players, except on "Defeat A Legend".
If you are put in a submission or anything that brings up the tap bar press A,X,B,Y at the same time to break out faster. This is helpful in royal rumbles because if you do it right you will never get thrown out.