Didn't see this on your list so...
You can also share points (not many people seem to know about it). If you get the galvaknuckles, you can share points. In the bank, to the right of the vault door as you enter, there is another security deposit box with 2 keys (like the deposit/withdraw box). If you punch the security deposit box it gives you the option to pay points. After you pay some points (in multiples of 1000), a money power-up appears in front of you and anyone can pick it up.
Same here, I seen it on a random website. You can try it out on solo though (although it would be pointless).
u know how nacht der untoten is on the right side of the corn field,,,? well whats on the left side because i noticed a path at the begining of the corn field on the left side... and my psn is OBEYxBigSean
It's basically where most of the Tower of Babel is based and it is where you can create a navcard table which no one knows what it does yet