On #1, the foot that is attached to all industrial and consumer quilting machines is a hopping foot. I have been doing quilting for nearly 7 years and I have never heard of a draining foot. Can you send a pic? This might be the same as a draining foot. A hopping foot should only cost you about $10-$15.
On #2, the cruise control is not a pcquilter product. If you can move the machine at the same speed in any direction, and do slight slowdowns at corners with a pause, you will not have any issue. This is how the PCQuilter works. The thread and needle will not break if you use the suggested hopping foot and YLI bobbin thread. The YLI bobbin thread is also referred to as Lingere Thread, but it is made by YLI. You can also use prewound bobbin embroidery thread.
On #3, it is very simple. When you have your top and bottom fabric stretched tight, you take a strap of elastic, pin it about 4" up from the takeup roller. Then you pull it tight enough under and over the side rail, and pin the other side about 4" up from the other end of the strap. DO NOT distort your fabric by pulling the elastic too tight. Just enough to eliminate the left and right distortion. You need to do a band on each side of the quilt.
Cheers,
Wade