Hope,
Happy to help. Yes your 1024 graphics will display correctly in the anamorphic timeline as they are the square pixel version of the 720 anamorphic as you have realised. Not sure what the blue line is. Does it show up on the output file?
In Compressor, you can change the pixel aspect to 720 x 405 which is true 16:9 square pixel by going to the geometry tab in the inspector and setting the frame size you want. Once you have your favorite settings, save that to use for all exports from this FCP setting. Do some tests.
If your source clips are all progressive, then yes, set field dominance to none and make sure the clips are also set to none.
If you Googled Michael Gizzing, then that is someone else. I am Gissing and yes I have some credits and enough knowledge to be a total nuisance sometimes.