This looks really interesting! I'll throw out a few things for you.
1. Back in 2011, I let my garden go fallow, and the Goosefoot grow. I grew a row for greens the year before, and the Goosefoot took over. In a roughly twenty by thirty plot, I harvested @ 5 lbs of unwinnowed seed. The seed is edible, but must be winnowed to get the shell containing saponin out.
2. The NA populations made extensive use of nuts and nut trees. Black Walnut, Hickory Nut, Chestnut, etc etc. Nuts were an important source of food for them.
3. Turkeys can be domesticated. If you rob a wild Turkey nest, preferably just before hatching, then keep them warm and allow them to hatch, you've got them. They imprint on the first being they see. That's an old family trick of mine, passed down over the generations.
4. Bison domestication. Man, great if it can occur, but really, really difficult. They are just so damned big and dangerous. Some folks have them as pets now, but the wildness will take generations to breed out, and in the meantime, how do you keep those bison who AREN"T being domesticated? I've seen an Angus bull go to his knees, stick his nose under a barbed wire stock fence, and stand up. Took several fence posts out of the ground, fence flattened, and the reason why? That cow on the other side of the fence was looking so, so bovinely delicious! The same thing goes for trying to keep bison in the domestication pen from getting out. Some animals just aren't made for domestication, I'll be very interested in how you do this one.
5. Metal working. Doable IMO. There is some evidence for it occurring IOTL IIRC. IOTL it was discovered, no reason this can't occur over here too.
You've probably already discovered all this, as it's obvious you've put in a lot of time in researching it, so apologies in advance if so. I'll be waiting for this TL to take off, it looks good!