It might be worth upgrading to the Professional Edition. I use the knife tool and get union of contours a lot to copy elements from one glyph to another, especially Serifs. Though you can join and break contours in the Home Edition, it is a bit labour intensive. (See the last two images in This Tutorial to learn how to join two contours in the Home Edition.
Another method that you can use in the Home Edition is to display a glyph in the Comparison Toolbar, turn off outline fills, and reduce the advance width of the current glyph to zero to overlay the comparison glyph on the current glyph. The illustration shows the F glyph overlayed on the E glyph while that is being edited.
Edit E Glyph.png
You can also use a background image in the same way.