Yep they are tangled lol, but I kind of enjoy ironing them, as someone above said I don't mind pressing scraps however I do not like to iron large backing pieces either

I don't pre-wash either

When I get a new bundle of scraps, I put them in a large lingerie bag and throw them in the dryer along with a wet washcloth (or two, depending on how many scraps there are) that was dampened w/ water and a little bit of fabric softener then set the dryer on high. All at once, the wrinkles are gone, any odors are removed, and any little "visitors" are killed by heat. Just removed from the dryer and smooth out the pieces while still warm.

you could put them into a mesh laundry bag to pre-wash them or a pillow case tied closed- that would keep the tangling-fraying down.
it is a personal choice really - but any fabrics i buy from somewhere other than (new-goods) i would wash ..ie: from thrift stores, yard sales...and yes ebay ect- if they have been in someones-house/barn/garage it would be best to wash them regardless of shrinkage/bleeding thoughts----for safety sake--

I put them in a large bowl of warm water, let them soak, then wrap them in a towel for a hour or so. They are ready to iron at that point. Spreading them out on the towel so if they run, you'll know.

I wouldn't wash. They will ravel up like crazy. When you finish the quilt, wash it in cold water and you should be OK. JMHO

Ditto