No. There are still people who are not online.

No it does but you have to do the sync that might come up after you click trophy collection for it to be visible to people who look at it online

iTunes, there 1.99 per episode.

You can find the detail of the visible light online at the Ucolick Organization website. Once on the page, you can learn details about light and it's wavelengths.

To prevent your information from being visible in an online background check, you will need to make sure the site you are using is a legitimate site. Make sure you have your virus protection on and also anti-phising software active.