Here's a click link to quilt you are looking at:
http://www.potterybarnkids.com/produ...gerHeroOverlay
That should be doable.
Some tips:
Flannel can shrink a *lot*. Especially since you don't intend to do a lot of quilting to hold the layers together, you will want to preshrink your flannel. It's a good idea to wash and dry flannel twice.
After washing, the flannel will become awfully limp. Whether or not you prewash, it's a good idea to heavily starch flannel before cutting. Starch stabilizes the fabric so you get more accurate cuts. Plus, flannel has a disturbing tendency to stretch and distort as you sew; heavy starching will keep your piecing accurate. My method for starching is to mix a 1:1 solution of Sta-Flo liquid laundry starch and water. I use a large wall painting brush to saturate the yardage with the starch mixture. Wait a minute to make sure that the fibers have absorbed the starch, then toss in the dryer. Iron with steam. Flannel can come out quite stiff this way which is ***good***. All of that starch will be gone when you wash the quilt after you are finished.
It's a good idea to use 1/2" seams with flannel -- especially with the large pieces in the quilt you are looking at. Flannel has a tendency to fray, and using 1/2" seams will prevent that problem.
Choose your batting carefully, especially if you will not be quilting moderately. Post here for suggestions when you get closer to that stage. It depends on how closely you will tie and/or quilt.
#3 in your post -- I'm not sure what you are thinking of doing. I suspect it is a mixture of techniques. What I would suggest is doing a search on the QB for "spray basting" and "basting with Elmer's glue". Those are two very good ways to layer your quilt before tying/quilting. I would recommend tying/quilting, and then either adding a binding to the edge or (if you have left extra backing fabric at the edges when layering), pulling the backing fabric to the top to bind the edges.
If you take it step-by-step and keep posting here, you should be fine!