Hi don...
1. No he one I used on mine is reversible... It’s so easy to remove as soon as you spray it. Just wipe it off. Later if you decide to remove it, you’ll have to use acetone based liquid (or a nail polish remover would do the trick). You won’t have to replace the lights. BUT make sure you use a quality product.
2. You’ll have to use some commonsense when you are doing this. Applying too many layers will definitely give you problems. Just with one coating, you won’t even notice that it’s tinted. As I mentioned earlier, you can do 2 or max three layers, not more than that. I had 2 layers on my previous ride. Check the pics of my car and the other black Lucino in the pics above.
@ EVO...
I got mine from Japan, cost me Yen 1500/- . I saw some tinting spray sold at the Sirasa Motor show recently, some modifying place from Kandana, Waththala area (not sure)
Problem with the tinted sheets are, you cannot get the perfect corners and it’ll leave air bubbles over raised imprints on the lights.
Make sure you’ll use a good quality product. As Don said you might have problems with the visibility or removing later. So better be careful. Mine was an original product and finish was so smooth. Better do a patch test on something else before you do the full.