I think what you mean is "productive" not "creative." If thats what you mean, I am with you. Obviously the more abstracted out low level details are, the more easier it is to churn out code, thus making you more productive.
But, given that you are using the same APIs (or using wrappers that utilize the same API, which is the same thing), I fail to see how you can do things differently in Scheme or some other language that you couldn't do in objective-c.
But, given that you are using the same APIs (or using wrappers that utilize the same API, which is the same thing), I fail to see how you can do things differently in Scheme or some other language that you couldn't do in objective-c.