Hello.
Thank you for your question, all of our lights are designed to work all year round so they will be fine outside all year.
Hello,
Yes, there is a on/off switch on the back of the light.
Hello.
You can, however, we would not usually recommend this as if you ever need to take the light off to perhaps change the battery/ change colour setting, it could damage where you have it.
Hello.
These lights are 12 Lumens.