Shirley poppy is also an option to my untrained eye ... ken https://www.google.com/search?q=Shirley+Poppies&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj1yPrFiuTNAhXJox4KHZlFBw8Q_AUICCgB&biw=902&bih=745&dpr=0.9

I'm leaning toward Euphorbia over toadflax for #3. The leaves are more sparse on the toadflax with more of a "regular leaf" look over that of a succulent. If it is a Euphorbia, it would have white sap. Toadflax doesn't.

spring beauty, Claytonia. I grew up with C. virginica, but yours is likely something different. Here's a series of maps from BONAP which shows all the US Claytonia. Bright green for the county where they occur, dark green if it occurs anywhere in the state. You can find your area and see which species grow in your county, then do a web search for those species to see which matches.

We call it Swamp Sunflower out here. Grows in the ditches and wild places. Continues to grow from the roots as well as drop seeds. Hardy. Perennial. Comes back faithfully. Can be cut back so that it stays lower to the ground if you only want flowers 18" high for example. Single stems easy to pull out if you want it thinned or have stragglers you don't want. Flowers are long blooming and look nice. Repeat bloomer especially if you deadhead. Heidi