1. I would say no. Often the markings are not all that accurate. What I would advise instead is to purchase woven ticking (the lines are actually woven into the fabric). I got some pretty pink at Beverly's online. Purchase enough for the width of your rails (mine are 10'); you should be able to cut all the leaders from that. Add on an extra foot, if you can afford it; the extra can be formed into very nice side tensioning devices. Here is a link to the ticking I purchased:
http://www.beverlys.com/james-thomps...paign=nextopia
2. My dh did this for me. There are some good directions on the Yahoo group homequiltingsystems, in their "files" section. I wouldn't worry about that until you get to that point.
3. It's not really necessary to mark centers on your leaders, but it's a nice thing to do. It's best to mark the centers ***after*** you attach the leaders to the rails. There is a Youtube video on how to do this. By using your machine to mark the centers on all of the leaders after they are attached, all of your markings will be lined up. The only reason to center your quilts on the frame is so that your frame stays balanced through many quiltings. I recommend purchasing the quilter's frame tape with markings (I will have to look it up to find the name) and mounting that tape on your frame after the leaders are on. It helps not only with centering, but also with keeping borders, blocks, etc. even as you roll.
4. I have used the zipper method. What I found is that my sewing machine, used to baste the quilt pieces to the zipper tape, had a serious tendency to stretch the fabric as it was sewn. The zipper tape has no stretch at all. Therefore, the tops and bottoms of both my backing and top tended to be wider than the middle of the quilt. When I did not use side tensioning to stretch the middles as well, I ended up with quilts that have "wings" at the corners. It is not that noticeable until I go to fold the finished quilts. Side tensioning would have helped with this. Currently I think it's much smarter to use either Red Snappers or Leader Grips. To use these, ***before*** attaching leaders to the frame, sew a 3/4" casing so you can insert the rod. I am planning to get myself some Red Snappers, as I think they will be a little easier for me to close with my weak hands. If you Google both these products, you will find some informative websites and videos. Either one will make loading a quilt easier and faster than using zippers (at about the same cost).