The plates can be found for up to 40% off sometimes. The 5" die has supposedly been fixed. I can't imagine putting it with the blade upside down. The two sides of the die are very different. I read that if you use a sheet of typing paper between the die and the fabric when using the rag die, it doesn't get so full of fibers.
As for waste, I think people have come up with ways to really reduce the waste. One big way is to use a sharpie to draw the die lines and then you can see exactly how much of the fabric is going to be cut off. The grain thing is definitely true-I read that you should put it on so the crosswise grain is parallel to the rollers. I think.