For the first one, it sounds like you just need to delete the original rectangle after creating the fill. Select the filled object, then Object > Ungroup to separate the two. Select just the outer rectangle and delete it. (It’s sometimes a little hard to select just the outline of an object like that. If you have trouble, click the hatch fill and select Object > Lower to bottom. Then, you should be able to select the outline easily.)
I’m not sure what you’re trying to do by setting the stroke to “no paint” — that makes the object hard to find, but the paths are still there in the document, and will be plotted.
As for filling with a pattern, that will not work. AxiDraw software does not plot fill colors, gradients, or patterns. You would need to find a way to convert that fill pattern into paths.