Sounds like you got your shit together!!! I've found that even paint made for plastics generally comes off very easy, I would suggest wrapping duct tape around it too. The only other thing I would suggest is next time starting them in grow plugs, Rockwool can be a pain in the ass plus the plugs are cheaper.:thumbsup:

P.S. the place you bought your grow light from has excellent customer service, Have been using them for years.