I do lots of PP and have never heard of using freezer paper. It would be way to heavy and not tear out from the seam. Others may have more info on a freezer paper method for you but it sounds weird to me.
I use either tracing paper or the packaged paper made for PP. Just use it in your copier and make as many copies as you need for your project. The idea of not removing the paper probably refers to the time untill you sew the blocks together. Then you remove the paper. I like to remove the 'inner paper' (not near seams) before sewing the sections into the blocks. Then tear the rest of the paper off after the sections are sewn into the finished blocks. I like to get rid of the paper after each block is completed because doing it all at the end of making the quilt is just tedious and miserable work. After removing the paper from the block I spray starch it on the back to help it hold its shape. After I complete the first row of blocks I will sew them together and countinue this row by row until the quilt is done.
Hope this helps some!
peace