For example, I took Spin the Wheel already and want to take it again. Is it possible?

As a shapeshifter you can:

Spin the wheel x1
Roll the bones x1

Going into form before you do so negates your opportunity to take these edges.

Both are very expensive edges.

With almost 100% certainty I say no. It is a one time deal unless the imms can step in and do something. I am pretty sure this is why many shifter players have a hard decision when it comes time for final forms. Also, this causes many people to Delete;Delete because they don't get the forms they want and roll the dice, then they get worse forms from the roll.

I hope someone proves me wrong though I would rather see people stick to a character then delete.