Help with ID n stuff

Most of these are probably going to be uprooted. The bed they're in right now is very long and narrow. It's dominated by three young black walnuts, three poorly performing blueberry bushes (to which I will be adding two more), a patch of sedum, some weigela, a hibiscus bush that I'm going to keep, several dozen sunflowers that are about to bloom, and these guys whom I don't know yet.

These grow in many other places on the property too, so I know there will be plenty around if I determine it's something I will find useful.

I'm primarily interested in plants with food value; but I also pay attention to plants that can be used for fuel or fiber, that have pharmaceutical benefits, or that are productive members of their plant community such as nitrogen fixers and pollinator attractors.

I've been pruning the lower branches of the black walnut in an effort to get them to grow tall and straight. I know that many plants can't stand to be grown near black walnut, but I've heard that grapes are not one of these. If this is true, I can plant some and train them up arbors to act as the understory. The hibiscus seems to be flourishing at the bush level, and the sedum looks good at the knee high level so I suppose I might replant some throughout the rest of the bed.

I'm not particularly impressed by the weigela; I don't believe this one was intentionally planted here, there is a bed with several bushes nearby. I don't really know of many beneficial uses to it, and will probably replace it with some hibiscus. Would I be better off with cuttings or seeds?

I don't know very much about blueberries. Our soil is generally alkaline but this bed seems to be mulched with some sort of pine bark so it might be more acidic. Of the three bushes, I saw three fruit on one and none on the others. The birds ate one and I ate the other two.

Southern Ohio.

Second plant. Some sort of grass.

Third plant.

This one looks like some sort of grass as well. I've never seen it before. At first I thought it was a young Virginia juniper peeking out from the grass.

Fifth plant.

Is this sumac? I'll know with certainty if it flowers I suppose.

This one grows everywhere. I don't know why there's a little voice in my head saying "some sorta lettuce" every time I see it. It doesn't look like any sort of lettuce I've ever eaten

I’m pretty sure of the following:

#2 barnyard grass, or crab grass, there are several types. Check out these links.
https://permies.com/t/90197/Loving-Crabgrass
http://www.eattheweeds.com/barnyard-grass/

#4 One of the Sedges, maybe Yellow Chufa. See the second link for my Chufa Woes.
http://www.eattheweeds.com/?s=chufa
https://permies.com/t/86909/Chuffa-Misadventure#714940

#6 Looks more like something in the Pecan family then Sumac to me. Do keep an eye out for those flowers though, just in case.

#7 Sow Thistle! Keep a look out for the signature flowers.
http://www.eattheweeds.com/?s=sow+thistle

How close are the walnuts to the blueberries?  The walnuts are toxic to them and many other plants.  
https://homeguides.sfgate.com/blueberries-compatible-black-walnut-trees-61029.html

I love black walnuts, but unless you have lots of room, they may not be the best choice in a yard. Besides the juglone, they get huge and the hulls are messy.

Nutsedge - a pretty little thing with white flowers in spring.  And it is prolific!  I mean PROLIFIC !!   Keep a few in a controlled area if you want to try them as an edible but   yank most of them  (easy to do after a spring rain) before those seeds dry and scatter EVERYWHERE.