I love this thread. I am 10 rows into mine right now. I subbed red Oasis (SWTC's soysilk worsted) for the Cotton Fleece because I wanted to knit something in soysilk. I'm wondering whether that will lessen the sleeve poufs due to the drape, but we shall see!
Just a little bit of clarification--it would not be a copyright issue, but rather a trademark one.
Copyrights accrue to "works of authorship"-the typical painting or book, or software code, whereas trademarks are rights that accrue to names, logos, other forms of identification. You might want to check out the wiki entry for a little more information: http://en.wikipedia.org/wiki/Trademark#Fundamental_concepts
From my perspective, selling something that has a college's name looks to be a technical violation of that college's trademark rights. Like CraftyChef said, it would be difficult to state or argue that the mere color combinations would be distinctive enough to become that college's trademark-but I'd stay away from advertising it as "an ISU bag" or using the college name, etc.
I used Timtex for the interfacing and I fused all of the layers together. I wouldn't recommend Timtex, though, b/c it has this weird lettucy texture which, when fused, is detectable in the outer fabric.
I use Timtex all the time, but I do not fuse it and therefore don't have to worry about the texture, If simply cut it to the same size as your outer fabric and sew it along with the outer fabric when doing your side seams (and bottom seams to "square" the bag in the Jordy pattern), I find that it stays put just fine.
Timtex is one of the things that they use in baseball caps, arrhythmia. I know there are some online places that sell it by the yard, it is 22" wide. I went to http://www.webofthread.com last time, and it was over $2.00 less per yard than at my local fabric store.
If you are using the Jordy pattern and something really stiff as interfacing, instead of leaving a side opening of the lining unstitched to pull the bag through, leave the bottom seam of the lining unstitched so that it's easier to pull the stiff fabric plus lining through to the right side. Best of luck, and I am excited for you!
the aventurine looks like amazonite???. I've been working with amazonite nuggets/teardrops and they have that same aqua/teal color, which looks absolutely gorgeous with carnelian (as in your necklace).
plastic needlepoint canvas is easily available and you can cut through it with a nice, sturdy pair of scissors. cut it to the dimensions of the bottom of your bag, and you can hot glue it in if you vary jordy's tutorial to sew the lining in last (rather than sewing the pieces right side together, and then pulling the outside of the purse through an opening in the lining). glue the plastic canvas before you sew the lining on.