Not really sure what you're after to be honest. If you add an effect, just drag the window that pops up away from the preview screen, then as you make changes you can see it 'live' on the preview window. If you've got a 2nd monitor drag the tools and effects windows over to there. Don't forget you can also click on the 'split preview' to give you before and after on each half of the preview.
Does that help?