Normally, you will only have a problem withdrawing a Chapter 7 filing if there are non-exempt assets that the trustee thinks can be sold to pay some of your debts (and the trustee fees).
It is very difficult to dismiss a Chapter 7 because the court requires you to prove that it would be better for the creditors, not you, to dismiss the case. Hope this perspective helps!
Yes. As was pointed out, there is not right to simply voluntarily withdraw a chapter 7 bankruptcy. Also, keep in mind, even if the court approved dismissal, the fact that you filed bankruptcy exists, so the credit report damage is done.
You do not have the absolute right to dismiss a chapter 7 case. If there are assets available to the trustee in the case the trustee's office may not allow a voluntary dismissal. You should speak to an experienced bankruptcy attorney in the jurisdiction in which you filed.