I had planned on having myself a nice little rant tonight, but after catching up on the last week or so of TV (and I completely forgot I have a binding to hand-sew) and making that zipless test bag, I've tired myself out and I need to go to bed instead of getting angry.
However, here is the bag as it turned out, with no interfacing, no zip and a belt bought for $2 from the salvos for a strap.
It's a bit lackluster, though I shoved an empty box of vita-wheats* into it to get an idea of what it would be like if it had stuff in it, and it made a big improvement.
Since these are really mainly meant to be test/display bags for people to pick what fabrics they want, I'm leaning towards doing half with and half without. But I love the belts as straps thing.
*because I use boxes of vita-wheats for all sorts of things.