Well, I've got three goals to go. One in London, one in San Franciso, one..

For the pro challenge just spine transfer from the farther bowl to the one next to it the spine transfer into the water tower, or use moon physics (superfly).

In san francisco, just go behind the stairs and thers this red bell wall ride it to set it off then go back and grind up one rail and down the other, but you have to be fast be because the guard runs to it and turns it off and runs back.

Im not sure about the cash thing, mini games can give you 500$ max so keep doing them untill it says youve collected all cash for the mini game.

Or go to the cheat thing on the options menu and type watch_me_xplode to unlock evrything including daisy.

I've beat every goal and ther is some sort of bonus for doing it.

A screen comes up that says there's one more secret character but first you gotta get all cash icons and do evry gap and get all the cash in all minigames.

I've done the mini game thing and have almost all the cash icons, but ive still got a few more gaps to go.

For the extra cash bit, there are plenty of ways to earn some. Play baseball with a dead guy in Alcatraz, bet on some rhinos at the zoo, bet on a cat fight in London, etc.