I will travel to the USA under Visa Waiver Program. Thus I will leave the US inside 90 days but for a number of reasons not relevant to this question I do not yet know exactly when I'll depart. Since one needs an onward flight from the USA to be admitted under the VWP I'll have to book one anyway.
I thought of booking a Economy Flex (Fare Rules) flight with Norwegian and canceling it as soon as I have been admitted.
Are there any problems with this plan? Will Norwegian refund the whole price or are there some fees or taxes that will be deducted or are not refundable? Will I be able to travel inside the US by plane?