Id be surprised if the clutch wasn't already slipping mad when you dump it., you'll need to replace it 110%, what model is it? If the shaft play is as minimal as you describe then that's fine, mines had a small amount of in and out for a while now and its still fine. I haven't heard of that problem with the dual zone but I know the plastic bit on my temp selector snapped behind the dash so its possible and yes its a dash out job so lots of $$ if your unlucky enough.