Is zoom teeth whitening safe for relatively thin enamel?

Your tooth enamel should not be affected by the Zoom whitening system. The structure of your enamel will not change only the yellow and dark stain molecules (chrompheres) trapped on the surface will be disrupted I do highly recommend following a desensitizing protocol prior to having the treatment as you may be more prone for sensitivity within the first day or so after the procedure due to having thin enamel in general.Looking forward to seeing photos of the before and afters!Good luck. 

You will not do any lasting damage to your enamel by Zoom whitening with thin enamel.  This procedure is only pulling out the surface stains.  The odds are that you will be more sensitive than most after the procedure due to the nature of having thin enamel.  After 24 hours the sensitivity should subside and you will have whiter teeth.  Good luck.