Sorry for the late reply everyone. Thanks so much for all the great input. Below I have attached several more pictures of the quilt. See the text for more detail.
For straps on the quilt all the negative comments are putting me off of it. One thing I would like to add however is some kind of method for securing the top ends together. I think that may be enough to give me the stability I want. I was also thinking of putting a few small pieces of sticky Velcro on the quilt and my sleeping pad to help keep them in line. I don't think this would add more than a 1/2 ounce and would also be removable if I didn't like it.
Next, I wanted to mention a few areas that I deviated from the backwoods daydreamer pattern on. For my quilt I turned it inside out after sewing three of the sides together. You can see the directions for that at this site under "light quilt" - http://www.backpacking.net/makegear.html. You'll notice in one of the below pictures how the seam does not show along the head section, only the line where it is turned inside out.
After turning the quilt inside out I sewed the remaining bottom side closed and moved on to the footbox, as outlined by backwoods daydreamer. One mistake I made with the project was not turning the footbox inside out the same way I did with the quilt. The result of this is that some of the insulation from the seam allowance shows on the outside of the quilt (as pictured). I'm not too worried about this though since it's only cosmetic. I singed the insulation with a lighter and I don't think fraying will be a problem, not that it would matter if it did fray. On my next quilt I will turn the footbox inside out on itself before sewing it to the rest of the quilt.
Finally, the backwoods daydreamer site adds some sort of tape along the seams as a final step. I skipped this step all together since most of my seams are not exposed as a result of turning the quilt inside out. For the remaining seams that are exposed I trust my stitching enough that I don't feel the need for reinforcement. Besides, I have a sewing machine I can fix any problems with.
I have not taken the quilt on an overnight trip yet. Based on the feel of the quilt compared to some other bags I have I think 20 degrees F will be a reasonable low end. Although that 20 degrees will not be without a tent or bivy sack and some extra layers.
The sizing on this quilt is big! Just look at the sleeping pad in the below pictures. One thing I am excited about is that my adventure medical kits bivy fits perfectly underneath the quilt. I'll really be able to push the temperature rating down without the quilt getting soaked by the vapor barrier liner. With a big puffy jacket and the AMK bivy I think I'll be able to get into the single digits comfortably.
Lots of info in this post but I hope it helps someone on their next project. Please let me know if there are anymore questions. Thanks for reading!