I have a late 2013 MBPr 15", with no screen coating problems. What I have learnt about screens is: don't touch them unless you really have to (except when it gets dusty, in which case wipe it off - gently - with a microfibre cloth). As for that one particle of dust that stays even after you've wiped it - which then leaves another one somewhere else - just walk away.
Keep your laptop away from food like oranges that squirt when you eat them (it's amazing how much food flies around when you eat). I always put a tea towel over the keyboard when I eat anywhere near it, and push it to the other side of the table so it is out of reach and not able to get messy. I have tea towels stained by Oyster sauce but my keyboard is pristine. 😀 I use a separate trackpad for navigation and am happy for it to get dirty as it can easily be cleaned/replaced if required.
On the rare occasions I have found something splashed onto the screen, I got a cotton bud dipped in water and cleaned just those spots. Then finished it off with a microfibre. I would NEVER use a damp cloth all over the screen because, to me, they are never the same afterwards; water stains. I also don't trust cleaning products.