No point in creating static variables that are not going to be used at the class level in any other classes, especially if they are inside a class that's parent is Script. Also, it's probably a good idea to be consistent with formatting, especially when making a tutorial (I am referring to your braces). It would be different if this was black box code, or something of the like.
Your walking method looks to be written poorly with static sleeps not accounting for movements or lag. I don't know how the walk method inside the api works, but you're explanation of it "tending to click until it's at the destination" can easily be remedied by not calling the method over and over if the current game destination is the tile you wanted to walk to.
Another thing, you may want to check if the object you're trying to click is on the screen before clicking it as that could cause problems.
Lastly, you could be stuck in an infinite loop with that banking method you've written. Instead, why not use a conditional sleep that times out after x seconds if the clients open method returns true?