If you wind up with bias edges on a quilt top, you would stabilize by running a row of stitches about 1/8" from the edge. Use a walking foot if you have one. This is commonly done as soon as the sandwich is complete. This is called stay stitching and is a common practice in garment construction.
When you attach a walking foot, be sure that you follow the manufacturer's instructions. Different machines, even by the same manufacturers will have a different way of attaching them. For instance, some have a bar that goes on top of the needle screw, and some go under. Also, be sure that you have the correct foot for your machine. This is one place where you are much better off paying the price to get the 'real deal' vs. a generic foot.