A:AnswerIf it's this particular product (Regular Switch) that you're asking for (just saying if Best Buy's comment/review system alters anything on their end), then no. The Switch Lite is considerably smaller.
A:AnswerYou don't have to buy any games to use the screen protector. The Zagg one is great because it is actually glass. When you apply it, it leaves no bubbles and it has a lifetime warranty for when it gets scratched or damaged.
A:AnswerTechnically no. It's got a wipe to clean the screen but that's it. I DO recommend doing this in a clean room with all air, including furnace/aircon off after you wash your hands as any dust or small particle will be a pain to get off as the backside of the screen protector is sticky and will catch particles. This is the downside of non-spray installs.
A:AnswerYes, it's a perfect fit up to 99%. All the playable screen will be covered and won't bother your gaming experience.
At the bottom of the Switch screen there are two notches on which you fit the screen, and all that section is very accurately protected.
