1. Every night before bed and in the morning before putting them on.
2. No. I had no difficulty putting them in but couldn't take them out. Others have difficulty putting them in.
3. In terms of visions? No side blindness. Much clearer. Don't have to keep adjusting them on your face. But they do dry out.
4. Have fun with them. I usually put my makeup on after but it is suggested to put it on before...you'll likely have more questions once you use them so ask again later! C: