Adding a fill to the repeat tile Illustrator CS6

Is it possible to create a fill inside the pattern editing mode without having to put a shape behind it? I know there is the alternative method of adding a fill after you create the repeat tile in the appearance panel but sometimes I like to see what the background fill would look like while I’m in the middle of creating the repeat.

Grouped Shapes / Outlines (Almost) Disappear After Creating Pattern?

I’ve selected a bunch of shapes and outlines for a pattern. I’ve gone to Object > Group, to group them all together, dragged them to the swatches panel to create a new swatch, and then after double-clicking that swatch, it brings up the Pattern Options panel. After approving the settings and clicking ‘Done’, the pattern is completely ruined, with most of the shapes reduced to a couple lines or nothing at all: