When I made the last import into my project in Sweet Home 3d, it was laying on the floor instead of standing upright, and the light was no longer colored the right color.

It's actually quite simple. Only when you have the brace&panel correct you do your last export. This means, in the correct position, set the correct colors, and have it in the right size. Only then export it. Basically, you import & export until the last export is 100% correct. This last export is what you import into your library.

Also, I think I jumped the gun on something. I selected the two brace files that were old but there was no way at all to delete them. I tried with the furniture library editor and I thought I had deleted their libraries, but those copies are still in the Sweet Home program and I don't know how to get them out of there. You can probably see them on the far left of a few of the pics I'm sending.

Click Menu>Help>About. On the dialog there is a button "Libraries", click it.
The dialog shows three lists, the top one shows all the libraries you have installed. You probably have one or more old libraries with the brace still installed. If so click that library, it should open a file manager in the Sweet Home 3D directory where the libraries are installed. Simply removing the library .sh3f file will remove the library. Restart Sweet Home 3D and they should be gone.

If you put the .sh3d and .sh3f file on dropbox I can take a look at them and see where it went wrong.