If you're not linked to Facebook then you don't have to worry about unlinking. When you get through an area and are blocked from going to the next area it will offer you a chance to advance for $.99 and one of the other choices is to do the quest levels. Once you complete those you can advance without paying.
EDIT: This posting should help...
http://www.mymommystyle.com/2013/10/...ebook-friends/