Keepvid or a YouTube downloading extension will download the video.
We can't live without the sunlight, it's natural that we need it. Because it make us warm in the cold weather, healthy, energy etc. So it's very important for us to have it, and it's like our heart as well.
The sun supplies all the energy used by living things on this earth. Either directly for the autotrophs or indirectly for the heterotrophs.
Few organisms, such as chemotrophs, bypass this system.